diff --git a/config.h b/config.h
index 39b11d87..e5e73c5e 100644
--- a/config.h
+++ b/config.h
@@ -456,7 +456,8 @@ NAMESPACE_END
 
 // Intrinsics availible in GCC 4.3 (http://gcc.gnu.org/gcc-4.3/changes.html) and
 //   MSVC 2008 (http://msdn.microsoft.com/en-us/library/bb892950%28v=vs.90%29.aspx)
-#if !defined(CRYPTOPP_DISABLE_SSE2) && !defined(CRYPTOPP_DISABLE_SSE4) && (((_MSC_VER >= 1500) && !defined(_M_ARM)) || defined(__SSE4_2__)) && (!defined(__SUNPRO_CC) || (defined(__SUNPRO_CC) && (__SUNPRO_CC >= 0x5130)))
+//   SunCC could generate SSE4 at 12.1, but the intrinsics are missing until 12.4.
+#if !defined(CRYPTOPP_DISABLE_SSE2) && !defined(CRYPTOPP_DISABLE_SSE4) && (((_MSC_VER >= 1500) && !defined(_M_ARM)) || defined(__SSE4_2__) || (__SUNPRO_CC >= 0x5130))
 	#define CRYPTOPP_BOOL_SSE4_INTRINSICS_AVAILABLE 1
 #else
 	#define CRYPTOPP_BOOL_SSE4_INTRINSICS_AVAILABLE 0
diff --git a/config.recommend b/config.recommend
index 4e24db31..94114bcb 100644
--- a/config.recommend
+++ b/config.recommend
@@ -456,7 +456,8 @@ NAMESPACE_END
 
 // Intrinsics availible in GCC 4.3 (http://gcc.gnu.org/gcc-4.3/changes.html) and
 //   MSVC 2008 (http://msdn.microsoft.com/en-us/library/bb892950%28v=vs.90%29.aspx)
-#if !defined(CRYPTOPP_DISABLE_SSE2) && !defined(CRYPTOPP_DISABLE_SSE4) && (((_MSC_VER >= 1500) && !defined(_M_ARM)) || defined(__SSE4_2__)) && (!defined(__SUNPRO_CC) || (defined(__SUNPRO_CC) && (__SUNPRO_CC >= 0x5130)))
+//   SunCC could generate SSE4 at 12.1, but the intrinsics are missing until 12.4.
+#if !defined(CRYPTOPP_DISABLE_SSE2) && !defined(CRYPTOPP_DISABLE_SSE4) && (((_MSC_VER >= 1500) && !defined(_M_ARM)) || defined(__SSE4_2__) || (__SUNPRO_CC >= 0x5130))
 	#define CRYPTOPP_BOOL_SSE4_INTRINSICS_AVAILABLE 1
 #else
 	#define CRYPTOPP_BOOL_SSE4_INTRINSICS_AVAILABLE 0