diff --git a/staticcheck/lint.go b/staticcheck/lint.go
index b3274c3e3..0dec8f26c 100644
--- a/staticcheck/lint.go
+++ b/staticcheck/lint.go
@@ -3154,7 +3154,7 @@ func CheckWriterBufferModified(pass *analysis.Pass) (interface{}, error) {
 
 func loopedRegexp(name string) CallCheck {
 	return func(call *Call) {
-		if len(extractConsts(call.Args[0].Value.Value)) == 0 {
+		if extractConst(call.Args[0].Value.Value) == nil {
 			return
 		}
 		if !isInLoop(call.Instr.Block()) {
diff --git a/staticcheck/rules.go b/staticcheck/rules.go
index 4bc6f7a5e..d4e4c1968 100644
--- a/staticcheck/rules.go
+++ b/staticcheck/rules.go
@@ -56,26 +56,28 @@ func (arg *Argument) Invalid(msg string) {
 
 type CallCheck func(call *Call)
 
-func extractConsts(v ir.Value) []*ir.Const {
+func extractConstExpectKind(v ir.Value, kind constant.Kind) *ir.Const {
+	k := extractConst(v)
+	if k == nil || k.Value == nil || k.Value.Kind() != kind {
+		return nil
+	}
+	return k
+}
+
+func extractConst(v ir.Value) *ir.Const {
 	v = irutil.Flatten(v)
 	switch v := v.(type) {
 	case *ir.Const:
-		return []*ir.Const{v}
+		return v
 	case *ir.MakeInterface:
-		return extractConsts(v.X)
+		return extractConst(v.X)
 	default:
 		return nil
 	}
 }
 
 func ValidateRegexp(v Value) error {
-	for _, c := range extractConsts(v.Value) {
-		if c.Value == nil {
-			continue
-		}
-		if c.Value.Kind() != constant.String {
-			continue
-		}
+	if c := extractConstExpectKind(v.Value, constant.String); c != nil {
 		s := constant.StringVal(c.Value)
 		if _, err := regexp.Compile(s); err != nil {
 			return err
@@ -85,13 +87,7 @@ func ValidateRegexp(v Value) error {
 }
 
 func ValidateTimeLayout(v Value) error {
-	for _, c := range extractConsts(v.Value) {
-		if c.Value == nil {
-			continue
-		}
-		if c.Value.Kind() != constant.String {
-			continue
-		}
+	if c := extractConstExpectKind(v.Value, constant.String); c != nil {
 		s := constant.StringVal(c.Value)
 		s = strings.Replace(s, "_", " ", -1)
 		s = strings.Replace(s, "Z", "-", -1)
@@ -104,13 +100,7 @@ func ValidateTimeLayout(v Value) error {
 }
 
 func ValidateURL(v Value) error {
-	for _, c := range extractConsts(v.Value) {
-		if c.Value == nil {
-			continue
-		}
-		if c.Value.Kind() != constant.String {
-			continue
-		}
+	if c := extractConstExpectKind(v.Value, constant.String); c != nil {
 		s := constant.StringVal(c.Value)
 		_, err := url.Parse(s)
 		if err != nil {
@@ -121,13 +111,7 @@ func ValidateURL(v Value) error {
 }
 
 func InvalidUTF8(v Value) bool {
-	for _, c := range extractConsts(v.Value) {
-		if c.Value == nil {
-			continue
-		}
-		if c.Value.Kind() != constant.String {
-			continue
-		}
+	if c := extractConstExpectKind(v.Value, constant.String); c != nil {
 		s := constant.StringVal(c.Value)
 		if !utf8.ValidString(s) {
 			return true
@@ -269,13 +253,7 @@ func validatePort(s string) bool {
 }
 
 func ValidHostPort(v Value) bool {
-	for _, k := range extractConsts(v.Value) {
-		if k.Value == nil {
-			continue
-		}
-		if k.Value.Kind() != constant.String {
-			continue
-		}
+	if k := extractConstExpectKind(v.Value, constant.String); k != nil {
 		s := constant.StringVal(k.Value)
 		_, port, err := net.SplitHostPort(s)
 		if err != nil {
@@ -296,17 +274,11 @@ func ConvertedFrom(v Value, typ string) bool {
 }
 
 func UniqueStringCutset(v Value) bool {
-	for _, c := range extractConsts(v.Value) {
-		if c.Value == nil {
-			continue
-		}
-		if c.Value.Kind() != constant.String {
-			continue
-		}
+	if c := extractConstExpectKind(v.Value, constant.String); c != nil {
 		s := constant.StringVal(c.Value)
 		rs := runeSlice(s)
 		if len(rs) < 2 {
-			continue
+			return true
 		}
 		sort.Sort(rs)
 		for i, r := range rs[1:] {