diff --git a/racket/src/racket/include/scheme.h b/racket/src/racket/include/scheme.h
index 2048a2d9ec..4001ae6705 100644
--- a/racket/src/racket/include/scheme.h
+++ b/racket/src/racket/include/scheme.h
@@ -63,8 +63,8 @@
 # define MZ_USE_SINGLE_FLOATS
 #endif
 
-/* gcc defines __SSE_MATH__ when SSE floating point is enabled: */
-#ifdef __SSE_MATH__
+/* gcc defines __SSE2_MATH__ when SSE2 floating point is enabled: */
+#ifdef __SSE2_MATH__
 # define C_COMPILER_USES_SSE 1
 #endif
 
diff --git a/racket/src/racket/sconfig.h b/racket/src/racket/sconfig.h
index 4010dc6752..38b7b30604 100644
--- a/racket/src/racket/sconfig.h
+++ b/racket/src/racket/sconfig.h
@@ -1311,9 +1311,9 @@
     converts (a == a) to TRUE, even if `a' is floating-point. Used
     only when USE_[SCO_]IEEE_FP_PREDS is not defined. */
 
- /* C_COMPILER_USES_SSE indicates that the C compiler generates SSE
+ /* C_COMPILER_USES_SSE indicates that the C compiler generates SSE2
     instructions for `double' arithmetic. This flag is turned on
-    automatically if __SSE_MATH__ is defined (usually by gcc). */
+    automatically if __SSE2_MATH__ is defined (usually by gcc). */
 
  /* MZ_LONG_DOUBLE enables extflonum support. */