diff --git a/eval_intern.h b/eval_intern.h
index 7259a79bee..c496d1389f 100644
--- a/eval_intern.h
+++ b/eval_intern.h
@@ -144,7 +144,11 @@ LONG WINAPI rb_w32_stack_overflow_handler(struct _EXCEPTION_POINTERS *);
 
 #define EC_REPUSH_TAG() (void)(_ec->tag = &_tag)
 
-#if defined __GNUC__ && __GNUC__ == 4 && (__GNUC_MINOR__ >= 6 && __GNUC_MINOR__ <= 8)
+#if defined __GNUC__ && __GNUC__ == 4 && (__GNUC_MINOR__ >= 6 && __GNUC_MINOR__ <= 8) || __clang__
+/* This macro prevents GCC 4.6--4.8 from emitting maybe-uninitialized warnings.
+ * This macro also prevents Clang from dumping core in EC_EXEC_TAG().
+ * (I confirmed Clang 4.0.1 and 4.0.0.)
+ */
 # define VAR_FROM_MEMORY(var) __extension__(*(__typeof__(var) volatile *)&(var))
 # define VAR_INITIALIZED(var) ((var) = VAR_FROM_MEMORY(var))
 # define VAR_NOCLOBBERED(var) volatile var