diff --git a/README.md b/README.md
index 9db9bce..e926732 100644
--- a/README.md
+++ b/README.md
@@ -16,7 +16,7 @@ which makes it suitable for use in high-integrity embedded systems.
 
 The codebase is implemented in C99/C11 following MISRA C:2012, with several intended deviations which are unavoidable
 due to the fact that a memory allocator has to rely on inherently unsafe operations to fulfill its purpose.
-The codebase is extremely compact (<500 SLoC) and is therefore trivial to validate.
+The codebase is extremely compact (<500 LoC) and is therefore trivial to validate.
 
 The allocator is designed to be portable across all conventional architectures, from 8-bit to 64-bit systems.
 Multi-threaded environments are supported with the help of external synchronization hooks provided by the application.
@@ -173,15 +173,18 @@ and its internal data structures are not damaged.
 
 ### Build configuration options
 
-The preprocessor options given below can be overridden (e.g., using the `-D` compiler flag, depending on the compiler)
-to fine-tune the implementation.
+The preprocessor options given below can be overridden to fine-tune the implementation.
 None of them are mandatory to use.
 
+#### O1HEAP_CONFIG_HEADER
+
+Define this optional macro like `O1HEAP_CONFIG_HEADER="path/to/my_o1heap_config.h"` to pass build configuration macros.
+This is useful because some build systems do not allow passing function-like macros via command line flags.
+
 #### O1HEAP_ASSERT(x)
 
 The macro `O1HEAP_ASSERT(x)` can be defined to customize the assertion handling or to disable it.
 To disable assertion checks, the macro should expand into `(void)(x)`.
-
 If not specified, the macro expands into the standard assertion check macro `assert(x)` as defined in `<assert.h>`.
 
 #### O1HEAP_LIKELY(x)
@@ -195,7 +198,7 @@ or into the original expression `(x)` if no such hinting is desired.
 If not specified, the macro expands as follows:
 
 - For some well-known compilers the macro automatically expands into appropriate branch weighting intrinsics.
-For example, for GCC, Clang, and ARM Compiler, it expands into `__builtin_expect((x), 1)`.
+  For example, for GCC, Clang, and ARM Compiler, it expands into `__builtin_expect((x), 1)`.
 - For other (unknown) compilers it expands into the original expression with no modifications: `(x)`.
 
 ## Development
@@ -256,6 +259,17 @@ An exception applies for the case of false-positive (invalid) warnings -- those
 - [Dynamic Memory Allocation In SQLite](https://sqlite.org/malloc.html) -- on Robson proof and deterministic fragmentation.
 - *[Russian]* [Динамическая память в системах жёсткого реального времени](https://habr.com/ru/post/486650/) -- issues with dynamic memory allocation in modern embedded RTOS and related popular misconceptions.
 
+## Changelog
+
+### v2.0
+
+- Remove critical section hooks to enhance MISRA conformance [#4](https://github.com/pavel-kirienko/o1heap/issues/4)
+- Add support for config header via `O1HEAP_CONFIG_HEADER` [#5](https://github.com/pavel-kirienko/o1heap/issues/5)
+
+### v1.0
+
+The first release.
+
 ## License
 
 The library is available under the terms of the MIT License.
diff --git a/o1heap/o1heap.c b/o1heap/o1heap.c
index 53801b1..37b5f7e 100644
--- a/o1heap/o1heap.c
+++ b/o1heap/o1heap.c
@@ -19,6 +19,12 @@
 
 // ---------------------------------------- BUILD CONFIGURATION OPTIONS ----------------------------------------
 
+/// Define this macro to include build configuration header. This is an alternative to the -D compiler flag.
+/// Usage example with CMake: "-DO1HEAP_CONFIG_HEADER=\"${CMAKE_CURRENT_SOURCE_DIR}/my_o1heap_config.h\""
+#ifdef O1HEAP_CONFIG_HEADER
+#    include O1HEAP_CONFIG_HEADER
+#endif
+
 /// The assertion macro defaults to the standard assert().
 /// It can be overridden to manually suppress assertion checks or use a different error handling policy.
 #ifndef O1HEAP_ASSERT
@@ -27,8 +33,6 @@
 #endif
 
 /// Branch probability annotations are used to improve the worst case execution time (WCET). They are entirely optional.
-/// A stock implementation is provided for some well-known compilers; for other compilers it defaults to nothing.
-/// If you are using a different compiler, consider overriding this value.
 #ifndef O1HEAP_LIKELY
 #    if defined(__GNUC__) || defined(__clang__) || defined(__CC_ARM)
 // Intentional violation of MISRA: branch hinting macro cannot be replaced with a function definition.
@@ -39,9 +43,7 @@
 #endif
 
 /// This option is used for testing only. Do not use in production.
-#if defined(O1HEAP_EXPOSE_INTERNALS) && O1HEAP_EXPOSE_INTERNALS
-#    define O1HEAP_PRIVATE
-#else
+#ifndef O1HEAP_PRIVATE
 #    define O1HEAP_PRIVATE static inline
 #endif
 
diff --git a/tests/.idea/dictionaries/pavel.xml b/tests/.idea/dictionaries/pavel.xml
index db13b8e..f32082d 100644
--- a/tests/.idea/dictionaries/pavel.xml
+++ b/tests/.idea/dictionaries/pavel.xml
@@ -12,6 +12,7 @@
       <w>unbin</w>
       <w>wcet</w>
       <w>wcmc</w>
+      <w>wmissing</w>
     </words>
   </dictionary>
 </component>
\ No newline at end of file
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index e4de496..0827fe5 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -78,21 +78,24 @@ function(gen_test name files compile_definitions compile_features compile_flags
     add_test("run_${name}" "${name}" --rng-seed time)
 endfunction()
 
-function(gen_test_matrix name files compile_definitions compile_flags)
-    gen_test("${name}_c99_x64" "${files}" "${compile_definitions}" c_std_99 "${compile_flags} -m64" "-m64")
-    gen_test("${name}_c99_x32" "${files}" "${compile_definitions}" c_std_99 "${compile_flags} -m32" "-m32")
-    gen_test("${name}_c11_x64" "${files}" "${compile_definitions}" c_std_11 "${compile_flags} -m64" "-m64")
-    gen_test("${name}_c11_x32" "${files}" "${compile_definitions}" c_std_11 "${compile_flags} -m32" "-m32")
+function(gen_test_matrix name files compile_definitions)
+    gen_test("${name}_c99_x64" "${files}" "${compile_definitions}" c_std_99 "-m64" "-m64")
+    gen_test("${name}_c99_x32" "${files}" "${compile_definitions}" c_std_99 "-m32" "-m32")
+    gen_test("${name}_c11_x64" "${files}" "${compile_definitions}" c_std_11 "-m64" "-m64")
+    gen_test("${name}_c11_x32" "${files}" "${compile_definitions}" c_std_11 "-m32" "-m32")
     # Coverage is only available for GCC builds.
     if ((CMAKE_CXX_COMPILER_ID STREQUAL "GNU") AND (CMAKE_BUILD_TYPE STREQUAL "Debug"))
-        gen_test("${name}_cov"
-                "${files}"
-                "${compile_definitions}"
-                c_std_11
-                "${compile_flags} -g -O0 --coverage"
-                "--coverage")
+        gen_test("${name}_cov" "${files}" "${compile_definitions}" c_std_11 "-g -O0 --coverage" "--coverage")
     endif ()
 endfunction()
 
-gen_test_matrix(test_private test_private.cpp O1HEAP_EXPOSE_INTERNALS=1 "-Wno-missing-declarations")
-gen_test_matrix(test_general test_general.cpp "" "")
+gen_test_matrix(
+        test_private
+        test_private.cpp
+        "O1HEAP_CONFIG_HEADER=\"${CMAKE_CURRENT_SOURCE_DIR}/cfg_test_internal.h\""
+)
+gen_test_matrix(
+        test_general
+        test_general.cpp
+        ""
+)
diff --git a/tests/cfg_test_internal.h b/tests/cfg_test_internal.h
new file mode 100644
index 0000000..f383dfe
--- /dev/null
+++ b/tests/cfg_test_internal.h
@@ -0,0 +1,7 @@
+// This is a config header for O1Heap. It is included from o1heap.c.
+
+#define O1HEAP_PRIVATE
+
+#ifdef __GNUC__
+#    pragma GCC diagnostic ignored "-Wmissing-declarations"  // NOLINT
+#endif