diff --git a/internal/resolver/dns/dns_resolver_test.go b/internal/resolver/dns/dns_resolver_test.go
index a4424d87a0f0..ffd6b0fe726c 100644
--- a/internal/resolver/dns/dns_resolver_test.go
+++ b/internal/resolver/dns/dns_resolver_test.go
@@ -734,7 +734,7 @@ func testDNSResolver(t *testing.T) {
 	for _, a := range tests {
 		b := NewBuilder()
 		cc := &testClientConn{target: a.target}
-		r, err := b.Build(resolver.Target{Endpoint: a.target, URL: *testutils.MustParseURL("scheme:///" + a.target)}, cc, resolver.BuildOptions{})
+		r, err := b.Build(resolver.Target{Endpoint: a.target, URL: *testutils.MustParseURL(fmt.Sprintf("scheme:///%s", a.target))}, cc, resolver.BuildOptions{})
 		if err != nil {
 			t.Fatalf("%v\n", err)
 		}
@@ -806,7 +806,7 @@ func TestDNSResolverExponentialBackoff(t *testing.T) {
 			cc := &testClientConn{target: test.target}
 			// Cause ClientConn to return an error.
 			cc.updateStateErr = balancer.ErrBadResolverState
-			r, err := b.Build(resolver.Target{Endpoint: test.target, URL: *testutils.MustParseURL("scheme:///" + test.target)}, cc, resolver.BuildOptions{})
+			r, err := b.Build(resolver.Target{Endpoint: test.target, URL: *testutils.MustParseURL(fmt.Sprintf("scheme:///%s", test.target))}, cc, resolver.BuildOptions{})
 			if err != nil {
 				t.Fatalf("Error building resolver for target %v: %v", test.target, err)
 			}
@@ -961,7 +961,7 @@ func testDNSResolverWithSRV(t *testing.T) {
 	for _, a := range tests {
 		b := NewBuilder()
 		cc := &testClientConn{target: a.target}
-		r, err := b.Build(resolver.Target{Endpoint: a.target, URL: *testutils.MustParseURL("scheme:///" + a.target)}, cc, resolver.BuildOptions{})
+		r, err := b.Build(resolver.Target{Endpoint: a.target, URL: *testutils.MustParseURL(fmt.Sprintf("scheme:///%s", a.target))}, cc, resolver.BuildOptions{})
 		if err != nil {
 			t.Fatalf("%v\n", err)
 		}
@@ -1045,7 +1045,7 @@ func testDNSResolveNow(t *testing.T) {
 	for _, a := range tests {
 		b := NewBuilder()
 		cc := &testClientConn{target: a.target}
-		r, err := b.Build(resolver.Target{Endpoint: a.target, URL: *testutils.MustParseURL("scheme:///" + a.target)}, cc, resolver.BuildOptions{})
+		r, err := b.Build(resolver.Target{Endpoint: a.target, URL: *testutils.MustParseURL(fmt.Sprintf("scheme:///%s", a.target))}, cc, resolver.BuildOptions{})
 		if err != nil {
 			t.Fatalf("%v\n", err)
 		}
@@ -1123,7 +1123,7 @@ func testIPResolver(t *testing.T) {
 	for _, v := range tests {
 		b := NewBuilder()
 		cc := &testClientConn{target: v.target}
-		r, err := b.Build(resolver.Target{Endpoint: v.target, URL: *testutils.MustParseURL("scheme:///" + v.target)}, cc, resolver.BuildOptions{})
+		r, err := b.Build(resolver.Target{Endpoint: v.target, URL: *testutils.MustParseURL(fmt.Sprintf("scheme:///%s", v.target))}, cc, resolver.BuildOptions{})
 		if err != nil {
 			t.Fatalf("%v\n", err)
 		}
@@ -1186,7 +1186,7 @@ func TestResolveFunc(t *testing.T) {
 	b := NewBuilder()
 	for _, v := range tests {
 		cc := &testClientConn{target: v.addr, errChan: make(chan error, 1)}
-		r, err := b.Build(resolver.Target{Endpoint: v.addr, URL: *testutils.MustParseURL("scheme:///" + v.addr)}, cc, resolver.BuildOptions{})
+		r, err := b.Build(resolver.Target{Endpoint: v.addr, URL: *testutils.MustParseURL(fmt.Sprintf("scheme:///%s", v.addr))}, cc, resolver.BuildOptions{})
 		if err == nil {
 			r.Close()
 		}
@@ -1225,7 +1225,7 @@ func TestDisableServiceConfig(t *testing.T) {
 	for _, a := range tests {
 		b := NewBuilder()
 		cc := &testClientConn{target: a.target}
-		r, err := b.Build(resolver.Target{Endpoint: a.target, URL: *testutils.MustParseURL("scheme:///" + a.target)}, cc, resolver.BuildOptions{DisableServiceConfig: a.disableServiceConfig})
+		r, err := b.Build(resolver.Target{Endpoint: a.target, URL: *testutils.MustParseURL(fmt.Sprintf("scheme:///%s", a.target))}, cc, resolver.BuildOptions{DisableServiceConfig: a.disableServiceConfig})
 		if err != nil {
 			t.Fatalf("%v\n", err)
 		}
@@ -1263,7 +1263,7 @@ func TestTXTError(t *testing.T) {
 		envconfig.TXTErrIgnore = ignore
 		b := NewBuilder()
 		cc := &testClientConn{target: "ipv4.single.fake"} // has A records but not TXT records.
-		r, err := b.Build(resolver.Target{Endpoint: "ipv4.single.fake", URL: *testutils.MustParseURL("scheme:///" + "ipv4.single.fake")}, cc, resolver.BuildOptions{})
+		r, err := b.Build(resolver.Target{Endpoint: "ipv4.single.fake", URL: *testutils.MustParseURL(fmt.Sprintf("scheme:///%s", "ipv4.single.fake"))}, cc, resolver.BuildOptions{})
 		if err != nil {
 			t.Fatalf("%v\n", err)
 		}
@@ -1299,7 +1299,7 @@ func TestDNSResolverRetry(t *testing.T) {
 	b := NewBuilder()
 	target := "ipv4.single.fake"
 	cc := &testClientConn{target: target}
-	r, err := b.Build(resolver.Target{Endpoint: target, URL: *testutils.MustParseURL("scheme:///" + target)}, cc, resolver.BuildOptions{})
+	r, err := b.Build(resolver.Target{Endpoint: target, URL: *testutils.MustParseURL(fmt.Sprintf("scheme:///%s", target))}, cc, resolver.BuildOptions{})
 	if err != nil {
 		t.Fatalf("%v\n", err)
 	}
@@ -1500,7 +1500,7 @@ func TestRateLimitedResolve(t *testing.T) {
 	b := NewBuilder()
 	cc := &testClientConn{target: target}
 
-	r, err := b.Build(resolver.Target{Endpoint: target, URL: *testutils.MustParseURL("scheme:///" + target)}, cc, resolver.BuildOptions{})
+	r, err := b.Build(resolver.Target{Endpoint: target, URL: *testutils.MustParseURL(fmt.Sprintf("scheme:///%s", target))}, cc, resolver.BuildOptions{})
 	if err != nil {
 		t.Fatalf("resolver.Build() returned error: %v\n", err)
 	}
@@ -1609,7 +1609,7 @@ func TestReportError(t *testing.T) {
 	cc := &testClientConn{target: target, errChan: make(chan error)}
 	totalTimesCalledError := 0
 	b := NewBuilder()
-	r, err := b.Build(resolver.Target{Endpoint: target, URL: *testutils.MustParseURL("scheme:///" + target)}, cc, resolver.BuildOptions{})
+	r, err := b.Build(resolver.Target{Endpoint: target, URL: *testutils.MustParseURL(fmt.Sprintf("scheme:///%s", target))}, cc, resolver.BuildOptions{})
 	if err != nil {
 		t.Fatalf("Error building resolver for target %v: %v", target, err)
 	}