diff --git a/gcc/config/i386/isc.h b/gcc/config/i386/isc.h
index 49d480af9a6..16f7142bbfd 100644
--- a/gcc/config/i386/isc.h
+++ b/gcc/config/i386/isc.h
@@ -56,9 +56,7 @@
 #undef TARGET_DEFAULT
 #define TARGET_DEFAULT 0201
 
-/* Define for XFmode extended real floating point support.
-   This will automatically cause REAL_ARITHMETIC to be defined.  */
 /* The ISC 2.0.2 software FPU emulator apparently can't handle
    80-bit XFmode insns, so don't generate them.  */
 #undef LONG_DOUBLE_TYPE_SIZE
-#define LONG_DOUBLE_TYPE_SIZE 6
+#define LONG_DOUBLE_TYPE_SIZE 64