diff --git a/tests/unit/test_toolchain.cpp b/tests/unit/test_toolchain.cpp
index 07878817e..a66317a41 100644
--- a/tests/unit/test_toolchain.cpp
+++ b/tests/unit/test_toolchain.cpp
@@ -34,6 +34,7 @@
 
 #include "test_util.h"
 #include "thread/topology.hpp"
+#include "utils/static_assert.hpp"
 
 extern "C" {
 uint32_t       otNetifAddress_Size_c();
@@ -51,7 +52,7 @@ void test_packed1()
         uint16_t mShort;
     } OT_TOOL_PACKED_END;
 
-    CompileTimeAssert(sizeof(packed_t) == 7, "packed_t should be packed to 7 bytes");
+    OT_STATIC_ASSERT(sizeof(packed_t) == 7, "packed_t should be packed to 7 bytes");
 
     VerifyOrQuit(sizeof(packed_t) == 7, "Toolchain::OT_TOOL_PACKED failed 1");
 }
@@ -65,7 +66,7 @@ void test_packed2()
         uint8_t mByte;
     } OT_TOOL_PACKED_END;
 
-    CompileTimeAssert(sizeof(packed_t) == 4, "packed_t should be packed to 4 bytes");
+    OT_STATIC_ASSERT(sizeof(packed_t) == 4, "packed_t should be packed to 4 bytes");
 
     VerifyOrQuit(sizeof(packed_t) == 4, "Toolchain::OT_TOOL_PACKED failed 2");
 }
@@ -88,7 +89,7 @@ void test_packed_union()
         } OT_TOOL_PACKED_FIELD;
     } OT_TOOL_PACKED_END;
 
-    CompileTimeAssert(sizeof(packed_t) == 5, "packed_t should be packed to 5 bytes");
+    OT_STATIC_ASSERT(sizeof(packed_t) == 5, "packed_t should be packed to 5 bytes");
 
     VerifyOrQuit(sizeof(packed_t) == 5, "Toolchain::OT_TOOL_PACKED failed 3");
 }
diff --git a/tests/unit/test_util.h b/tests/unit/test_util.h
index c54a8c18f..6e155cf5f 100644
--- a/tests/unit/test_util.h
+++ b/tests/unit/test_util.h
@@ -72,15 +72,6 @@ extern "C" {
         }                                                                               \
     } while (false)
 
-//#define CompileTimeAssert(COND, MSG) typedef char __C_ASSERT__[(COND)?1:-1]
-
-// I would use the above definition for CompileTimeAssert, but I am getting the following errors
-// when I run 'make -f examples/Makefile-posix distcheck':
-//
-//      error: typedef "__C_ASSERT__" locally defined but not used [-Werror=unused-local-typedefs]
-//
-#define CompileTimeAssert(COND, MSG)
-
 #ifdef __cplusplus
 }
 #endif