diff --git a/test/state/precompiles.cpp b/test/state/precompiles.cpp
index 638af9afd..a995e8cb5 100644
--- a/test/state/precompiles.cpp
+++ b/test/state/precompiles.cpp
@@ -317,19 +317,61 @@ ExecutionResult expmod_execute(
     const uint8_t* input, size_t input_size, uint8_t* output, size_t output_size) noexcept
 {
     static constexpr auto LEN_SIZE = sizeof(intx::uint256);
+    static constexpr auto HEADER_SIZE = 3 * LEN_SIZE;
+    static constexpr auto LEN32_OFF = LEN_SIZE - sizeof(uint32_t);
 
     // The output size equal to the modulus size.
+    const auto mod_len = output_size;
+
     // Handle short incomplete input up front. The answer is 0 of the length of the modulus.
-    if (output_size == 0 || input_size <= 3 * LEN_SIZE) [[unlikely]]
+    if (input_size <= HEADER_SIZE) [[unlikely]]
+    {
+        std::fill_n(output, output_size, 0);
+        return {EVMC_SUCCESS, output_size};
+    }
+
+    const auto base_len = intx::be::unsafe::load<uint32_t>(&input[LEN32_OFF]);
+    const auto exp_len = intx::be::unsafe::load<uint32_t>(&input[LEN_SIZE + LEN32_OFF]);
+    assert(intx::be::unsafe::load<uint32_t>(&input[2 * LEN_SIZE + LEN32_OFF]) == mod_len);
+
+    const bytes_view payload{input + HEADER_SIZE, input_size - HEADER_SIZE};
+    const size_t mod_off = base_len + exp_len;  // Cannot overflow if gas cost computed before.
+    const auto mod_explicit = payload.substr(std::min(mod_off, payload.size()), mod_len);
+
+    // Handle the mod being zero early.
+    // This serves two purposes:
+    // - bigint libraries don't like zero modulus because division by 0 is not well-defined,
+    // - having non-zero modulus guarantees that base and exp aren't out-of-bounds.
+    if (mod_explicit.find_first_not_of(uint8_t{0}) == bytes_view::npos) [[unlikely]]
     {
+        // The modulus is zero, so the result is zero.
         std::fill_n(output, output_size, 0);
         return {EVMC_SUCCESS, output_size};
     }
 
+    const auto mod_requires_padding = mod_explicit.size() != mod_len;
+    if (mod_requires_padding) [[unlikely]]
+    {
+        // The modulus is the last argument and some of its bytes may be missing and be implicitly
+        // zero. In this case, copy the explicit modulus bytes to the output buffer and pad the rest
+        // with zeroes. The output buffer is guaranteed to have exactly the modulus size.
+        const auto [_, output_p] = std::ranges::copy(mod_explicit, output);
+        std::fill(output_p, output + output_size, 0);
+    }
+
+    const auto base = payload.substr(0, base_len);
+    const auto exp = payload.substr(base_len, exp_len);
+    const auto mod = mod_requires_padding ? bytes_view{output, mod_len} : mod_explicit;
+
 #ifdef EVMONE_PRECOMPILES_SILKPRE
+    (void)base;
+    (void)exp;
+    (void)mod;
+    // For Silkpre use the raw input for compatibility.
     return silkpre_expmod_execute(input, input_size, output, output_size);
 #else
-    return expmod_stub(input, input_size, output, output_size);
+    expmod_stub(base, exp, mod, output);
+    return {EVMC_SUCCESS, mod.size()};
 #endif
 }
 
diff --git a/test/state/precompiles_stubs.cpp b/test/state/precompiles_stubs.cpp
index 4fe832758..188f972ef 100644
--- a/test/state/precompiles_stubs.cpp
+++ b/test/state/precompiles_stubs.cpp
@@ -3,371 +3,121 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #include "precompiles_stubs.hpp"
-#include "../utils/utils.hpp"
-#include "hash_utils.hpp"
 #include <algorithm>
+#include <cassert>
 #include <iostream>
-#include <span>
 
 namespace evmone::state
 {
-using test::operator""_hex;
-
 namespace
 {
-struct HashedInputStubs : std::unordered_map<hash256, bytes>
+/// Returns the expmod result for the known inputs or empty bytes if not found.
+///
+/// Missing inputs collected with:
+/// bin/evmone-statetest test_dirs >/dev/null 2> >(sort | uniq | tee stub.txt)
+///
+/// Results computed with:
+/// ```python
+/// def e(s):
+///     b, x, m = s.split(",")
+///     b = int(b, 16) if b != "0x" else 0
+///     x = int(x, 16) if x != "0x" else 0
+///     m = int(m, 16) if m != "0x" else 0
+///     r = 0
+///     if m != 0:
+///         r = pow(b, x, m)
+///     print(f'{{"{s}","{r:02x}"}},')
+/// ```
+bytes expmod_lookup_result(bytes_view base, bytes_view exp, bytes_view mod)
 {
-    using unordered_map::unordered_map;
+    static const std::unordered_map<std::string_view, std::string_view> stubs{
+        // clang-format off
+        {"0x02,0x01,0x02","00"},
+        {"0x02,0x01,0x03","02"},
+        {"0x02,0x02,0x02","00"},
+        {"0x02,0x02,0x05","04"},
+        {"0x02,0x03,0x06","02"},
+        {"0x03,0x05,0x64","2b"},
+        {"0x03,0x1c93,0x61", "5f"},
+        {"0x03,0x2700,0x9c00","6801"},
+        {"0x03,0x7114,0x2d3b","1b"},
+        {"0x03,0xffff,0x8000000000000000000000000000000000000000000000000000000000000000","3b01b01ac41f2d6e917c6d6a221ce793802469026d9ab7578fa2e79e4da6aaab"},
+        {"0x03,0x4000000000000000000000000000000000000000000000000000000000000000,0x010000000000000000000000000000000000000000000000000000000000000000","01"},
+        {"0x03,0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2e,0xffffffffffffffffffffffffffffffffffffffffff2f00000000000000000000","162ead82cadefaeaf6e9283248fdf2f2845f6396f6f17c4d5a39f820b6f6b5f9"},
+        {"0x03,0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2e,0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f","01"},
+        {"0x09,0x0e7f,0x90f7","8615"},
+        {"0x09,0x90f7,0x90f7","1c3b"},
+        {"0x09,0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff97,0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff97","09"},
+        {"0x31,0x0961,0x0961","00"},
+        {"0xba,0xee,0xd000","9000"},
+        {"0xba,0xee,0xd00000","100000"},
+        {"0xba,0xee,0xd00100","789700"},
+        {"0x1001,0x0100,0x10","01"},
+        {"0x1bd0,0x90f7,0x61","50"},
+        {"0x9100,0x578b,0x55f0","3e80"},
+        {"0x9100,0x90f7,0x61","5f"},
+        {"0x9100,0x90f7,0x90f7","1c3b"},
+        {"0x9c00,0x01,0xd7a1","9c00"},
+        {"0xd796,0xd796,0xa7d5","866a"},
+        {"0x02534f82b1,0x013f20d9c7d18d62cd95674d2e,0x013f20d9c7d18d62cd95674d2f","01"},
+        {"0xd935b43e42,0x204fcbfb734a6e27735e8e90,0x204fcc1fd2727bb040f9eecb","01"},
+        {"0x0846813a8d2d,0x451387340fa0,0x597c6545ae63","01"},
+        {"0x010000000000000000000000000000000000000000000000000000000000000000,0x01,0x304d37f120d696c834550e63d9bb9c14b4f9165c9ede434e4644e3998d6db881","0e7de84a5bcf0e16fa56b80cbf55f39877229030e5a8af78a0a78e003cdb657b"},
+        {"0x304d37f120d696c834550e63d9bb9c14b4f9165c9ede434e4644e3998d6db876,0x304d37f120d696c834550e63d9bb9c14b4f9165c9ede434e4644e3998d6db876,0xfffffffffffffffffffffffffffffffffffffff5","cd433bbd1fa6457602a79d957ee85a37e2496d0a"},
+        {"0x035ee4e488f45e64d2f07becd54646357381d32f30b74c299a8c25d5202c04938e,0xf6c4764a04f10fc908b78c4486886000,0xf6d290251a79681a83b950c7e5c37351","01"},
+        {"0x0785e45de3d6be050ba3c4d33ff0bb2d,0x010ace3b1dfe9c49f4c7a8075102fa19a86c,0x010ace3b1dfe9c49f4c7a8075102fa19a86d","01"},
+        {"0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffa0,0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff97,0x61","3e"},
+        {"0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffa0,0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff97,0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff97","09"},
+        // clang-format on
+    };
+
+    /// Combine the arguments into a key. It can be copy-pasted to python's pow().
+    const auto key = "0x" + evmc::hex({base.data(), base.size()}) +  //
+                     ",0x" + evmc::hex({exp.data(), exp.size()}) +   //
+                     ",0x" + evmc::hex({mod.data(), mod.size()});    //
 
-    ExecutionResult lookup(bytes_view input, uint8_t* output, size_t max_output_size) const
+    const auto it = stubs.find(key);
+    if (it == stubs.end())
     {
-        if (const auto it = find(keccak256(input)); it != end())
-        {
-            if (it->second.size() > max_output_size)
-                return {EVMC_INTERNAL_ERROR, 0};  // invalid stub entry.
-            std::ranges::copy(it->second, output);
-            return {EVMC_SUCCESS, it->second.size()};
-        }
-        return {EVMC_PRECOMPILE_FAILURE, 0};  // not found, treat as a failure.
+        std::cerr << "expmod: no result for " << key << "\n";
+        return {};
     }
-};
+    return evmc::from_hex(it->second).value();
+}
 }  // namespace
 
-ExecutionResult expmod_stub(
-    const uint8_t* input, size_t input_size, uint8_t* output, size_t max_output_size) noexcept
+
+void expmod_stub(bytes_view base, bytes_view exp, bytes_view mod, uint8_t* output) noexcept
 {
-    static const HashedInputStubs stubs{
-        {0x010d1c26efabac677596f64e2e4f8894606e3636370a8665756ebc184e745aba_bytes32,
-            "000000000001"_hex},
-        {0x033274602281965ae0382e28ea7584792e3d846b4ead2f1529e0d61a63afa9b9_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x034d54cdad5956fb28f9060287fad9073c1e87fb7c6d1709e00f362c9052aff7_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000001"_hex},
-        {0x03c85b4c0caf8657ff29b05743c33f9ffbb8df604c46cc86caa2f051e6a065a8_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x067b3e4d57e1fe2d23c71a95cdd86c8019a649e466d5fcf8e22cce66ceea36fc_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000001"_hex},
-        {0x08774b45b9263bbdd4f040b01c444d167f20686daf1d9dc0be2703ac5b79898f_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000001"_hex},
-        {0x0ea4f1fe8ab439ed65bf736c2d1e75244a52fec0e96cefadf09ea5d170956d52_bytes32,
-            "0e7de84a5bcf0e16fa56b80cbf55f39877229030e5a8af78a0a78e003cdb657b"_hex},
-        {0x0f38b3a063df12614121ae2d0cd202213a5fa95e3536e0f82c3bbffb311f9152_bytes32, "02"_hex},
-        {0x0ff064739dbad34456d55c4dafd7d33b7e0e7c63b18a1252ef9fd8bc88867234_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000009"_hex},
-        {0x10eab4762daae8abab287dd86a83326a78f5bbb8641f38a6792819576c94e35a_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000001"_hex},
-        {0x12292042f822da16c3db8dc1fc978be48218e0fb997cfff35857e16abba41300_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000001"_hex},
-        {0x12993abd44b4858730eb18a794ee686dc20b54cfee0e75a1f2e345cf9568ecc1_bytes32, "01"_hex},
-        {0x12fc00c16a89e602782828a84667390d4a14bf74c1fd16dab784c7ebae45de06_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x130508100dd1f8b1c72b7eb16f82ee3b8a6f3bcbc8461c9f02c06f14ead89d75_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x1403e9d046887460408ff2c1956a064def64c4bb221b7bdff146b097b3a282c5_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000001"_hex},
-        {0x1669beee2b904266bc5a6eef210d6869ccea5c9a25e173d940428ccfbd6310c4_bytes32, "0000"_hex},
-        {0x180fd71813c81062f2cdf852bc03fb8e8b8b98d21436001e255dc7141cb299d7_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x18c5b4c6cf9fccb97b1cf7f966b2ca8e951365e13eaf63ec93d3fd4ad87fadb5_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x18ca0a599a7bcdfd7e487cafca8ab1dfb6ef18074841fc3da95b73479eee3270_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x1a949941ca6b99c817a4e16cefe478308222535d19f1437ae2fdd892cb8ac789_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000001"_hex},
-        {0x1d885466c9ed74249248ad01d298eb4f509d9102a849d767f893da1e78799a9d_bytes32, "0002"_hex},
-        {0x1e2d85db0c7c63bcc2054bf2d3caaf5d61920c77bb16f10572e6115458b0c352_bytes32, "00"_hex},
-        {0x1e6d8ff8f706b4b423086b9c725a43e4aa6ce504b790612fb0e6f738cafa5b00_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x1ea137b55c9c2a68d4dd701fc31c5a11a2fcb3f9cc4c2fe6b2bf968d250ece35_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x1fe8359bcf1145edd7e23e4c32df953ea82d5db7a0d840ebe1d436f73bf93c5d_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x216ff577ab4b6adc22902060367bba5d514a67cb53b6171bc62569e58ce1a8ce_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000001"_hex},
-        {0x21879cfde84f139c4c53262a49dff3c774b0e2949fce670e2f471e54f1ffbc23_bytes32, "00"_hex},
-        {0x21915510d6f6b58738bc790d97df3881396743ef975eb2a4d7dd0cd4bc10bc4b_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000001"_hex},
-        {0x244fa8474b97c1fc5589e3372062373bc939e2c2c8d51733cb62dd1af06d93ae_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x251828ea0fa55eeff4920c784f29d02b3d462893b0a53b35da407951f670d4c3_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x251f23d45faa62fd4edee6c7ca9d0e522dd618b21ca79c0ececcf6b4ab1d418e_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x2559c03f8499faccfb5d86c5a9c6857b9882045939b54fcab26046debc586400_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x25612858eb4e5086b12e02d2fbb70b8b64bb55022fdd629ec789f2c84607688f_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x26d4791888c6a5a6dad93c613727e1025a5e629993ace97b6f60a168ba5b643b_bytes32, "3e"_hex},
-        {0x274f35379f9c71d56060a980068aa27bbb6b0163485b566c98f23208d9afebe8_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000001"_hex},
-        {0x27611fee3bcae57830f4acede0e4ddc28d6b80307e4e3c24518ff8427870b1a2_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x2815ce44f31ea08706a5b434ba9241be790bb99a9a14f2abc58f44e4c7ed5258_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000001"_hex},
-        {0x2aa26dd05f29718306030f45826699e7cfa5cee2d7e693743f08ca1890c70471_bytes32, "00"_hex},
-        {0x2bbbf3147d86f35e028afe730dbe8a309c343a5af574d686b4de6f0299f44b62_bytes32, "00"_hex},
-        {0x2e2b0152d440cb2300acb1a66f126dc6a55d48429cd4d1c65a6b08b1d70faa1a_bytes32, "00"_hex},
-        {0x2e7668b70ebbbf0427b7206105b43be56ed44866084aef806b455c4302bb09ed_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x2ebcffbe9bfd10639c61895d63dc4adbea44b1ef949f81ec56b684a553ac3325_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x2fa614a47cc9c85b69679204e1ef9ac927b19471ded492b8ece1e8e67262fb51_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x31d7d7f3d30e2f6915813b0eae348106f9c36033685f734d666df55950721e09_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000009"_hex},
-        {0x35de80ebb4a020482ef20b08e76ccf3047a069603f0f298ca69d20d652e8d84b_bytes32,
-            "00000000000000000000000001"_hex},
-        {0x39d0581989c293b89482bfa1e116cec4009a18aa00b89c5242b7fe5c3766ed7e_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000001"_hex},
-        {0x39e4706fe515d7364d5d89bca544e81f9ef187062620ac4e97b4c64e9dba668a_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x3b41faafc90d54978545a2f7f0a0fbc5710b148872dd6e1d6c2ec4c94fee3617_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000001"_hex},
-        {0x3b73107bd69d6198ed057833aac40d0dcdc99e568c5e4f2ff154688bbab5fb26_bytes32,
-            "000000000000000000000000000000000000000000000000000000000000000001"_hex},
-        {0x3bf09109c39d56015c8905aa26907c8f8c509e4a54ff4efee2f896a8b1176042_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x3cc1cc331ba2e9897c734d97dfb178fecedbc4cc90c706eee0c6059c94b36297_bytes32, "0000"_hex},
-        {0x3d8f5d715374acba3f92a425b8bad30eae5f2f534a63c4cea5ad4401fe46ad75_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x4084709b90b82b198ec95c387a53f65e5492611a56a9bf34a46d7c5fa02907dd_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000001"_hex},
-        {0x418b0655db32fa5820ed237053dfe34869c9a1c39460ed8d58e6e87e5164f8ec_bytes32,
-            "00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x4262e4bfbfbc25391172acaa697e2b36c9aa60be165a81de92f9a6be0ed447ca_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x42c4e39cf1e2224199b3895508025d4cf89fc21154dd0ba0c9f86ebbe81667a1_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x42d09d5551133d4982c7c496aa710fdeb46c2974fa2ee405bd0cf2d8687f5eb4_bytes32, "0000"_hex},
-        {0x469eae86b1701336b3d583df4527d639b1cccca716608b728563a0eeeeeb55ba_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000001"_hex},
-        {0x4798efaf9795653086f314b2a745a3c677befc3a143f8e71f6961410234d4aa7_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x48cbcce9cddcfc87a9dfb28f8c07a498c6cae91c3577410009e009de8ae15426_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000001"_hex},
-        {0x48d102df204080cb58f6131e8de27892647da0958ab111e3b7604279fe7638d9_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000001"_hex},
-        {0x49daba1e38b9fdb769584f02a5cf0d5ccc52e1dcc5f1683c384e308cbda1aefb_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x4a4e7e22f228bbfeef1e2e652aeb39630a3fea4545ce98694e34b3a13cbf4d9c_bytes32,
-            "162ead82cadefaeaf6e9283248fdf2f2845f6396f6f17c4d5a39f820b6f6b5f9"_hex},
-        {0x4b1c0353029df7c0e24c97c1caa608b2447a736abd6ec92c6a6ad19c74af6764_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000001c3b"_hex},
-        {0x4c1451f2f475e314e13ab026083f0e75042da3757331579bcc2acf982eb93e47_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000001"_hex},
-        {0x4d26511722a244d920d5b388b5008248c71b7232df5e2dad0c68731ecea7baca_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x4e895772ea04e2bebc4494c0f61d649af0ec15eb35e3d6fb23ccd43cec8fc477_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000001"_hex},
-        {0x4e9bc8aacd818468cd54729198300a542eaa7ed24d172b0fa62eaca18c80320f_bytes32, "0000"_hex},
-        {0x560aefbbe4dc7910322f1a57808798dd21e6f20b6804497d76feb28109d9e4b4_bytes32, "00"_hex},
-        {0x56cd39d56e15e186eb742169736637742fe0129e3816caa42199e1d11444a087_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000001"_hex},
-        {0x57f24ba6197dd6bca4b92b2b069547c4d9715cb715b118fd06b6c506f3fe9a6f_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000001"_hex},
-        {0x58dca178acf545c5f569bf230c25f4b299df65d50427e5599c062de84ae8e117_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0x59083a31c083633493c1f0fff98188fc553195939b97664ddf4f1f7372fdb9ed_bytes32, "00"_hex},
-        {0x5913b435dbacbaf8a060c4901cb61a7aeea4f64e04bed5194a9cda0e3f7407b9_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
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-            "cd433bbd1fa6457602a79d957ee85a37e2496d0a"_hex},
-        {0xf9adfd03d4d3cf7e9245f9677b882459f0f0ea492b36ebbe34fe965bf3b4e05c_bytes32,
-            "000000000000000000000000000000000000000000000000000000000000002b"_hex},
-        {0xfa22beaea48d8a5e37b2f00efdc83600d4a9d1e1ff5a08cea987db6e6d168833_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000001"_hex},
-        {0xfaccb2379850753cd96f3a4f37dd3f431863cab480cd1f808f696b0cafab5da4_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0xfb859356d00b38d191345159ca428ce6b47c7c03000e91d93ba541f2db07ee75_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0xfc08a758057657032bc36068292a2e3dfa490f21697d4e5841ce2bcbf50b12ba_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0xfc94ce88596dbda4103ce1ee25fe0f05e0d8e1a57a2d8660d45800ef89ea2f64_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-        {0xfe0d647b508fe5dbc76db4136a295fcc960ec1990c7639bb8ddcd06c1761e9e5_bytes32,
-            "0000000000000000000000000000000000000000000000000000000000000000"_hex},
-    };
-    return stubs.lookup({input, input_size}, output, max_output_size);
+    // Keep the output size before the mod normalization.
+    const auto output_size = mod.size();
+
+    // Normalize arguments by removing leading zeros.
+    base = base.substr(std::min(base.find_first_not_of(uint8_t{0}), base.size()));
+    exp = exp.substr(std::min(exp.find_first_not_of(uint8_t{0}), exp.size()));
+    mod = mod.substr(std::min(mod.find_first_not_of(uint8_t{0}), mod.size()));
+    assert(!mod.empty());  // mod must not be 0.
+
+    // Figure out the result by handling trivial cases
+    // or finally looking it up in the predefined set of results.
+    const auto result = [&]() -> bytes {
+        // For mod == 1 the result is 0.
+        if (mod.size() == 1 && mod[0] == 1)
+            return bytes{};
+
+        // For exp == 0 and mod > 1 the result is 1.
+        if (exp.empty())
+            return bytes{1};
+
+        // For base <= 1, exp != 0, mod > 1 the result is base.
+        if (base.empty() || (base.size() == 1 && base[0] == 1))
+            return bytes{base};
+
+        return expmod_lookup_result(base, exp, mod);
+    }();
+
+    // Set the result in the output buffer.
+    const auto output_p = std::fill_n(output, output_size - result.size(), 0);
+    std::ranges::copy(result, output_p);
 }
 }  // namespace evmone::state
diff --git a/test/state/precompiles_stubs.hpp b/test/state/precompiles_stubs.hpp
index 5920f6360..461c31e5d 100644
--- a/test/state/precompiles_stubs.hpp
+++ b/test/state/precompiles_stubs.hpp
@@ -7,6 +7,9 @@
 
 namespace evmone::state
 {
-ExecutionResult expmod_stub(
-    const uint8_t* input, size_t input_size, uint8_t* output, size_t max_output_size) noexcept;
+using evmc::bytes;
+using evmc::bytes_view;
+
+/// Executes the expmod precompile for trivial and pre-defined inputs.
+void expmod_stub(bytes_view base, bytes_view exp, bytes_view mod, uint8_t* output) noexcept;
 }  // namespace evmone::state
diff --git a/test/unittests/precompiles_expmod_test.cpp b/test/unittests/precompiles_expmod_test.cpp
index 8122a0e8f..252e69b1c 100644
--- a/test/unittests/precompiles_expmod_test.cpp
+++ b/test/unittests/precompiles_expmod_test.cpp
@@ -8,52 +8,51 @@
 #include <test/state/precompiles_internal.hpp>
 #include <test/utils/utils.hpp>
 
-struct TestCase
+TEST(expmod, test_vectors)
 {
-    std::string base;
-    std::string exp;
-    std::string mod;
-    std::string expected_result;
-};
-
-/// Test vectors for expmod precompile.
-/// TODO: Currently limited to what expmod_stub can handle, but more can be added along the proper
-///   implementation, e.g. {"03", "1c93", "61", "5f"}.
-static const std::vector<TestCase> test_cases{
-    {"", "", "", ""},
-    {"", "", "00", "00"},
-    {"02", "01", "03", "02"},
+    struct TestCase
     {
-        "03",
-        "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2e",
-        "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
-        "0000000000000000000000000000000000000000000000000000000000000001",
-    },
-};
+        std::string_view base_hex;
+        std::string_view exp_hex;
+        std::string_view mod_hex;
+        std::string_view expected_result_hex;
+    };
 
-TEST(expmod, test_vectors)
-{
-    for (const auto& [base, exp, mod, expected_result] : test_cases)
+    /// Test vectors for expmod precompile.
+    const std::vector<TestCase> test_cases{
+        {"", "", "", ""},
+        {"", "", "00", "00"},
+        {"02", "01", "03", "02"},
+        {"03", "1c93", "61", "5f"},
+        {
+            "03",
+            "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2e",
+            "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
+            "0000000000000000000000000000000000000000000000000000000000000001",
+        },
+    };
+
+    for (const auto& [base_hex, exp_hex, mod_hex, expected_result_hex] : test_cases)
     {
-        const auto base_bytes = *evmc::from_hex(base);
-        const auto exp_bytes = *evmc::from_hex(exp);
-        const auto mod_bytes = *evmc::from_hex(mod);
-        const auto expected_result_bytes = *evmc::from_hex(expected_result);
+        const auto base = *evmc::from_hex(base_hex);
+        const auto exp = *evmc::from_hex(exp_hex);
+        const auto mod = *evmc::from_hex(mod_hex);
+        const auto expected_result = *evmc::from_hex(expected_result_hex);
 
         evmc::bytes input(3 * 32, 0);
-        input[31] = static_cast<uint8_t>(base_bytes.size());
-        input[32 + 31] = static_cast<uint8_t>(exp_bytes.size());
-        input[64 + 31] = static_cast<uint8_t>(mod_bytes.size());
-        input += base_bytes;
-        input += exp_bytes;
-        input += mod_bytes;
+        input[31] = static_cast<uint8_t>(base.size());
+        input[32 + 31] = static_cast<uint8_t>(exp.size());
+        input[64 + 31] = static_cast<uint8_t>(mod.size());
+        input += base;
+        input += exp;
+        input += mod;
 
-        evmc::bytes result(expected_result_bytes.size(), 0xfe);
-        const auto r =
+        evmc::bytes result(expected_result.size(), 0xfe);
+        const auto [status, output_size] =
             evmone::state::expmod_execute(input.data(), input.size(), result.data(), result.size());
-        EXPECT_EQ(r.status_code, EVMC_SUCCESS);
-        EXPECT_EQ(r.output_size, expected_result_bytes.size());
-        EXPECT_EQ(hex(result), expected_result);
+        EXPECT_EQ(status, EVMC_SUCCESS);
+        EXPECT_EQ(output_size, expected_result.size());
+        EXPECT_EQ(hex(result), expected_result_hex);
     }
 }
 
@@ -87,3 +86,43 @@ TEST(expmod, analysis_oog)
         EXPECT_GT(gas_cost, GAS_LIMIT);
     }
 }
+
+TEST(expmod, incomplete_inputs)
+{
+    struct TestCase
+    {
+        std::string_view input_hex;
+        std::string_view expected_result_hex;
+    };
+
+    // Tests for expmod with raw and incomplete inputs (requires padding input with zero bytes).
+    static constexpr auto GAS_LIMIT = 100'000'000;
+    const std::vector<TestCase> inputs{
+        // clang-format off
+        {"", ""},
+        {"0000000000000000000000000000000000000000000000000000000000000001 0000000000000000000000000000000000000000000000000000000000000001 0000000000000000000000000000000000000000000000000000000000000001", "00"},
+        {"0000000000000000000000000000000000000000000000000000000000000001 0000000000000000000000000000000000000000000000000000000000000001 0000000000000000000000000000000000000000000000000000000000000001 ba ee", "00"},
+        {"0000000000000000000000000000000000000000000000000000000000000001 0000000000000000000000000000000000000000000000000000000000000001 0000000000000000000000000000000000000000000000000000000000000002 ba ee d0", "9000"},
+        {"0000000000000000000000000000000000000000000000000000000000000001 0000000000000000000000000000000000000000000000000000000000000001 0000000000000000000000000000000000000000000000000000000000000003 ba ee d000", "100000"},
+        {"0000000000000000000000000000000000000000000000000000000000000001 0000000000000000000000000000000000000000000000000000000000000001 0000000000000000000000000000000000000000000000000000000000000003 ba ee d001", "789700"},
+        {"0000000000000000000000000000000000000000000000000000000000000001 0000000000000000000000000000000000000000000000000000000000000001 0000000000000000000000000000000000000000000000000000000000000003 ba ee 00d0", "009000"},
+        {"0000000000000000000000000000000000000000000000000000000000000001 0000000000000000000000000000000000000000000000000000000000000001 0000000000000000000000000000000000000000000000000000000000000003 ba ee 0000", "000000"},
+        {"0000000000000000000000000000000000000000000000000000000000000001 0000000000000000000000000000000000000000000000000000000000000001 0000000000000000000000000000000000000000000000000000000000000003 ba ee 000000 fe", "000000"},
+        {"0000000000000000000000000000000000000000000000000000000000000010 0000000000000000000000000000000000000000000000000000000000000010 0000000000000000000000000000000000000000000000000000000000000001 0000000000000000000000000000000001", "00"},
+        {"000000000000000000000000000000000000000000000000000000000000ffff 0000000000000000000000000000000000000000000000000000000000000001 0000000000000000000000000000000000000000000000000000000000000001 80", "00"},
+        // clang-format on
+    };
+
+    for (const auto& [input_hex, expected_result_hex] : inputs)
+    {
+        const auto input = evmc::from_spaced_hex(input_hex).value();
+        const auto [gas_cost, max_output_size] = evmone::state::expmod_analyze(input, EVMC_PRAGUE);
+        EXPECT_LT(gas_cost, GAS_LIMIT);
+        auto output = std::make_unique_for_overwrite<uint8_t[]>(max_output_size);
+        const auto [status, output_size] = evmone::state::expmod_execute(
+            input.data(), input.size(), output.get(), max_output_size);
+        EXPECT_EQ(status, EVMC_SUCCESS);
+        const auto result_hex = evmc::hex({output.get(), output_size});
+        EXPECT_EQ(result_hex, expected_result_hex);
+    }
+}