diff --git a/scst/include/backport.h b/scst/include/backport.h
index ebc5ce719..e9df7bce0 100644
--- a/scst/include/backport.h
+++ b/scst/include/backport.h
@@ -218,13 +218,14 @@ static inline void *bsg_job_sense(struct bsg_job *job)
  * pseudo keyword for switch/case use") # v5.4
  */
 #ifndef fallthrough
-#ifdef __has_attribute
+#if __GNUC__ >= 5
 #if __has_attribute(__fallthrough__)
 #define fallthrough __attribute__((__fallthrough__))
 #else
 #define fallthrough do {} while (0)  /* fallthrough */
 #endif
 #else
+/* gcc 4.x doesn't support __has_attribute() */
 #define fallthrough do {} while (0)  /* fallthrough */
 #endif
 #endif