diff --git a/src/dsp/dsp.h b/src/dsp/dsp.h
index 1fbe6adf..7dc09e03 100644
--- a/src/dsp/dsp.h
+++ b/src/dsp/dsp.h
@@ -32,9 +32,19 @@ extern "C" {
 # define LOCAL_GCC_PREREQ(maj, min) \
     (LOCAL_GCC_VERSION >= (((maj) << 8) | (min)))
 #else
+# define LOCAL_GCC_VERSION 0
 # define LOCAL_GCC_PREREQ(maj, min) 0
 #endif
 
+#ifdef __clang__
+# define LOCAL_CLANG_VERSION ((__clang_major__ << 8) | __clang_minor__)
+# define LOCAL_CLANG_PREREQ(maj, min) \
+    (LOCAL_CLANG_VERSION >= (((maj) << 8) | (min)))
+#else
+# define LOCAL_CLANG_VERSION 0
+# define LOCAL_CLANG_PREREQ(maj, min) 0
+#endif  // __clang__
+
 #if defined(_MSC_VER) && _MSC_VER > 1310 && \
     (defined(_M_X64) || defined(_M_IX86))
 #define WEBP_MSC_SSE2  // Visual C++ SSE2 targets
diff --git a/src/utils/endian_inl.h b/src/utils/endian_inl.h
index f7061ba9..cd56c37f 100644
--- a/src/utils/endian_inl.h
+++ b/src/utils/endian_inl.h
@@ -35,25 +35,13 @@
 #endif
 
 #if !defined(HAVE_CONFIG_H)
-#ifdef __GNUC__
-# define LOCAL_GCC_VERSION ((__GNUC__ << 8) | __GNUC_MINOR__)
-#else
-# define LOCAL_GCC_VERSION 0
-#endif  // __GNUC__
-
-#ifdef __clang__
-# define LOCAL_CLANG_VERSION ((__clang_major__ << 8) | __clang_minor__)
-#else
-# define LOCAL_CLANG_VERSION 0
-#endif  // __clang__
-
 // clang-3.3 and gcc-4.3 have builtin functions for swap32/swap64
-#if LOCAL_GCC_VERSION >= 0x403 || LOCAL_CLANG_VERSION >= 0x303
+#if LOCAL_GCC_PREREQ(4,3) || LOCAL_CLANG_PREREQ(3,3)
 #define HAVE_BUILTIN_BSWAP32
 #define HAVE_BUILTIN_BSWAP64
 #endif
 // clang-3.3 and gcc-4.8 have a builtin function for swap16
-#if LOCAL_GCC_VERSION >= 0x408 || LOCAL_CLANG_VERSION >= 0x303
+#if LOCAL_GCC_PREREQ(4,8) || LOCAL_CLANG_PREREQ(3,3)
 #define HAVE_BUILTIN_BSWAP16
 #endif
 #endif  // !HAVE_CONFIG_H