diff --git a/tests/test.cpp b/tests/test.cpp
index ad0c18249..a1a10ba30 100644
--- a/tests/test.cpp
+++ b/tests/test.cpp
@@ -1240,7 +1240,7 @@ void TestError_(const char *src, const char *error_substr, const char *file,
   TestError_(src, error_substr, false, file, line, func);
 }
 
-#ifdef WIN32
+#ifdef _WIN32
 #  define TestError(src, ...) \
     TestError_(src, __VA_ARGS__, __FILE__, __LINE__, __FUNCTION__)
 #else
diff --git a/tests/test_assert.h b/tests/test_assert.h
index 5a9610e1f..883586b0e 100644
--- a/tests/test_assert.h
+++ b/tests/test_assert.h
@@ -21,7 +21,7 @@
 #define TEST_NOTNULL(exp) TestEq(exp == NULL, false, #exp, __FILE__, __LINE__)
 #define TEST_EQ_STR(exp, val) TestEqStr(exp, val, #exp, __FILE__, __LINE__)
 
-#ifdef WIN32
+#ifdef _WIN32
   #define TEST_ASSERT_FUNC(exp) TestEq(exp, true, #exp, __FILE__, __LINE__, __FUNCTION__)
   #define TEST_EQ_FUNC(exp, val) TestEq(exp, val, #exp, __FILE__, __LINE__, __FUNCTION__)
 #else