diff --git a/target-i386/helper.c b/target-i386/helper.c
index 4656596eb1baa8dfc9e4bba9c99804ac735db6d5..968d3991faad1e122e74b8c91b53185aa4baf083 100644
--- a/target-i386/helper.c
+++ b/target-i386/helper.c
@@ -21,6 +21,11 @@
 
 //#define DEBUG_PCALL
 
+#if defined(__sparc__) && (HOST_SOLARIS < 10)
+#include <ieeefp.h>
+#define isinf(x) (fpclass(x) == FP_NINF || fpclass(x) == FP_PINF)
+#endif 
+
 #if 0
 #define raise_exception_err(a, b)\
 do {\