diff --git a/src/cmd/compile/internal/gc/reflect.go b/src/cmd/compile/internal/gc/reflect.go
index cd39969258..5ca292c39e 100644
--- a/src/cmd/compile/internal/gc/reflect.go
+++ b/src/cmd/compile/internal/gc/reflect.go
@@ -1068,7 +1068,7 @@ ok:
 			ot += 4 // align for *rtype
 		}
 
-		dataAdd := (inCount + outCount) * Widthptr
+		dataAdd := (inCount + t.Outtuple) * Widthptr
 		ot = dextratype(s, ot, t, dataAdd)
 
 		// Array of rtype pointers follows funcType.
diff --git a/src/reflect/all_test.go b/src/reflect/all_test.go
index 352b2046e7..32dd782c3c 100644
--- a/src/reflect/all_test.go
+++ b/src/reflect/all_test.go
@@ -2410,6 +2410,17 @@ func TestEmbeddedMethods(t *testing.T) {
 	}
 }
 
+type FuncDDD func(...interface{}) error
+
+func (f FuncDDD) M() {}
+
+func TestNumMethodOnDDD(t *testing.T) {
+	rv := ValueOf((FuncDDD)(nil))
+	if n := rv.NumMethod(); n != 1 {
+		t.Fatalf("NumMethod()=%d, want 1", n)
+	}
+}
+
 func TestPtrTo(t *testing.T) {
 	var i int