diff --git a/include/ruby/ruby.h b/include/ruby/ruby.h
index 27c62397ac..1cc9937acb 100644
--- a/include/ruby/ruby.h
+++ b/include/ruby/ruby.h
@@ -360,7 +360,7 @@ rb_fix2ulong(VALUE x)
 #define RB_POSFIXABLE(f) ((f) < RUBY_FIXNUM_MAX+1)
 #define RB_NEGFIXABLE(f) ((f) >= RUBY_FIXNUM_MIN)
 #if defined HAVE_BUILTIN___BUILTIN_ADD_OVERFLOW
-# define RB_FIXABLE(f) ({SIGNED_VALUE c; !__builtin_add_overflow((f), (f), &c);})
+# define RB_FIXABLE(f) ({SIGNED_VALUE a=(f),c; !__builtin_add_overflow(a, a, &c);})
 #else
 # define RB_FIXABLE(f) (RB_POSFIXABLE(f) && RB_NEGFIXABLE(f))
 #endif