diff --git a/CHANGELOG.md b/CHANGELOG.md
index c170218..e024b7d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+### Changed
+- embedded-test no longer enables default `heapless` and `serde-json-core` features.
+- the panic handler should no longer use `defmt::Display2Format`.
+
 ## [0.6.1]
 
 ### Added
diff --git a/Cargo.lock b/Cargo.lock
index c4fc396..7a49d93 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -165,7 +165,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0bfb9eb618601c89945a70e254898da93b13be0388091d42117462b265bb3fad"
 dependencies = [
  "hash32",
- "serde",
  "stable_deref_trait",
 ]
 
@@ -254,7 +253,6 @@ version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5b81787e655bd59cecadc91f7b6b8651330b2be6c33246039a65e5cd6f4e0828"
 dependencies = [
- "heapless",
  "ryu",
  "serde",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 6e037a4..3ddff88 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,8 +15,8 @@ default-target = "riscv32imac-unknown-none-elf"
 semihosting = { version = "0.1.7", features = ["args"], optional = true }
 embedded-test-macros = { version = "0.6.1", path = "./macros" }
 serde = { version = "1.0.193", default-features = false, features = ["derive"] }
-serde-json-core = "0.6.0"
-heapless = "0.8.0"
+serde-json-core = { version = "0.6.0", default-features = false }
+heapless = { version = "0.8.0", default-features = false }
 
 # Optional dependencies
 defmt = { version = "1", optional = true }
diff --git a/examples/esp32c6/Cargo.lock b/examples/esp32c6/Cargo.lock
index 1412f2a..1f36996 100644
--- a/examples/esp32c6/Cargo.lock
+++ b/examples/esp32c6/Cargo.lock
@@ -662,7 +662,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0bfb9eb618601c89945a70e254898da93b13be0388091d42117462b265bb3fad"
 dependencies = [
  "hash32",
- "serde",
  "stable_deref_trait",
 ]
 
@@ -940,7 +939,6 @@ version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5b81787e655bd59cecadc91f7b6b8651330b2be6c33246039a65e5cd6f4e0828"
 dependencies = [
- "heapless",
  "ryu",
  "serde",
 ]
diff --git a/examples/std/Cargo.lock b/examples/std/Cargo.lock
index e52669f..9be0006 100644
--- a/examples/std/Cargo.lock
+++ b/examples/std/Cargo.lock
@@ -134,7 +134,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0bfb9eb618601c89945a70e254898da93b13be0388091d42117462b265bb3fad"
 dependencies = [
  "hash32",
- "serde",
  "stable_deref_trait",
 ]
 
@@ -195,7 +194,6 @@ version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5b81787e655bd59cecadc91f7b6b8651330b2be6c33246039a65e5cd6f4e0828"
 dependencies = [
- "heapless",
  "ryu",
  "serde",
 ]
diff --git a/examples/stm32f767/Cargo.lock b/examples/stm32f767/Cargo.lock
index f994167..a1a07f9 100644
--- a/examples/stm32f767/Cargo.lock
+++ b/examples/stm32f767/Cargo.lock
@@ -320,7 +320,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0bfb9eb618601c89945a70e254898da93b13be0388091d42117462b265bb3fad"
 dependencies = [
  "hash32",
- "serde",
  "stable_deref_trait",
 ]
 
@@ -502,7 +501,6 @@ version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5b81787e655bd59cecadc91f7b6b8651330b2be6c33246039a65e5cd6f4e0828"
 dependencies = [
- "heapless",
  "ryu",
  "serde",
 ]
diff --git a/src/lib.rs b/src/lib.rs
index df1e3e6..1e4a7e8 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -13,12 +13,8 @@ pub use embedded_test_macros::tests;
 fn panic(info: &core::panic::PanicInfo) -> ! {
     error!("====================== PANIC ======================");
 
-    #[cfg(not(feature = "defmt"))]
     error!("{}", info);
 
-    #[cfg(feature = "defmt")]
-    error!("{}", defmt::Display2Format(info));
-
     semihosting::process::abort()
 }