diff --git a/CMakeLists.txt b/CMakeLists.txt
index 52ff13e21..27091adf4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.10)
 
 set(PROJECT_NAME shadowsocks-libev)
 set(RELEASE_DATE 2026-02-09)
diff --git a/cmake/FindPCRE2.cmake b/cmake/FindPCRE2.cmake
index a89e93542..848ca8e74 100644
--- a/cmake/FindPCRE2.cmake
+++ b/cmake/FindPCRE2.cmake
@@ -5,9 +5,9 @@
 #   PCRE2_INCLUDE_DIRS
 #   PCRE2_LIBRARIES
 
-include(FindPkgConfig)
+find_package(PkgConfig QUIET)
 
-if(PKG_CONFIG_FOUND)
+if(PkgConfig_FOUND)
     pkg_check_modules(_PCRE2 QUIET libpcre2-8)
 endif()
 
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 436dc99a1..d2a0199d4 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -18,6 +18,8 @@ function(ss_add_test name sources libs)
     add_executable(${name} ${sources})
     target_compile_definitions(${name} PRIVATE -DHAVE_CONFIG_H)
     target_link_libraries(${name} ${libs})
+    # Keep assertions enabled for tests even in Release builds.
+    target_compile_options(${name} PRIVATE -UNDEBUG)
     add_test(NAME ${name} COMMAND ${name})
 endfunction()