diff --git a/modules/openapi-generator/src/main/resources/go/client.mustache b/modules/openapi-generator/src/main/resources/go/client.mustache
index 799553a189e3..62f75508baef 100644
--- a/modules/openapi-generator/src/main/resources/go/client.mustache
+++ b/modules/openapi-generator/src/main/resources/go/client.mustache
@@ -111,7 +111,7 @@ func selectHeaderAccept(accepts []string) string {
 // contains is a case insensitive match, finding needle in a haystack
 func contains(haystack []string, needle string) bool {
 	for _, a := range haystack {
-		if strings.ToLower(a) == strings.ToLower(needle) {
+		if strings.EqualFold(a, needle) {
 			return true
 		}
 	}
diff --git a/modules/openapi-generator/src/main/resources/go/signing.mustache b/modules/openapi-generator/src/main/resources/go/signing.mustache
index d7171ca5350c..d8c5b376e9e6 100644
--- a/modules/openapi-generator/src/main/resources/go/signing.mustache
+++ b/modules/openapi-generator/src/main/resources/go/signing.mustache
@@ -136,7 +136,7 @@ func (h *HttpSignatureAuth) ContextWithValue(ctx context.Context) (context.Conte
 	}
 	m := make(map[string]bool)
 	for _, h := range h.SignedHeaders {
-		if strings.ToLower(h) == strings.ToLower(HttpHeaderAuthorization) {
+		if strings.EqualFold(h, HttpHeaderAuthorization) {
 			return nil, fmt.Errorf("Signed headers cannot include the 'Authorization' header")
 		}
 		m[h] = true
diff --git a/samples/client/petstore/go/go-petstore/client.go b/samples/client/petstore/go/go-petstore/client.go
index c656e9616cac..f872380df96a 100644
--- a/samples/client/petstore/go/go-petstore/client.go
+++ b/samples/client/petstore/go/go-petstore/client.go
@@ -119,7 +119,7 @@ func selectHeaderAccept(accepts []string) string {
 // contains is a case insensitive match, finding needle in a haystack
 func contains(haystack []string, needle string) bool {
 	for _, a := range haystack {
-		if strings.ToLower(a) == strings.ToLower(needle) {
+		if strings.EqualFold(a, needle) {
 			return true
 		}
 	}
diff --git a/samples/openapi3/client/extensions/x-auth-id-alias/go-experimental/client.go b/samples/openapi3/client/extensions/x-auth-id-alias/go-experimental/client.go
index dc4affb7bd50..547180d6b63e 100644
--- a/samples/openapi3/client/extensions/x-auth-id-alias/go-experimental/client.go
+++ b/samples/openapi3/client/extensions/x-auth-id-alias/go-experimental/client.go
@@ -104,7 +104,7 @@ func selectHeaderAccept(accepts []string) string {
 // contains is a case insensitive match, finding needle in a haystack
 func contains(haystack []string, needle string) bool {
 	for _, a := range haystack {
-		if strings.ToLower(a) == strings.ToLower(needle) {
+		if strings.EqualFold(a, needle) {
 			return true
 		}
 	}
diff --git a/samples/openapi3/client/petstore/go/go-petstore/client.go b/samples/openapi3/client/petstore/go/go-petstore/client.go
index a2a56c5af959..c6d7fabcb2ef 100644
--- a/samples/openapi3/client/petstore/go/go-petstore/client.go
+++ b/samples/openapi3/client/petstore/go/go-petstore/client.go
@@ -122,7 +122,7 @@ func selectHeaderAccept(accepts []string) string {
 // contains is a case insensitive match, finding needle in a haystack
 func contains(haystack []string, needle string) bool {
 	for _, a := range haystack {
-		if strings.ToLower(a) == strings.ToLower(needle) {
+		if strings.EqualFold(a, needle) {
 			return true
 		}
 	}
diff --git a/samples/openapi3/client/petstore/go/go-petstore/signing.go b/samples/openapi3/client/petstore/go/go-petstore/signing.go
index f2610ce7742f..d6dfdbb50f95 100644
--- a/samples/openapi3/client/petstore/go/go-petstore/signing.go
+++ b/samples/openapi3/client/petstore/go/go-petstore/signing.go
@@ -145,7 +145,7 @@ func (h *HttpSignatureAuth) ContextWithValue(ctx context.Context) (context.Conte
 	}
 	m := make(map[string]bool)
 	for _, h := range h.SignedHeaders {
-		if strings.ToLower(h) == strings.ToLower(HttpHeaderAuthorization) {
+		if strings.EqualFold(h, HttpHeaderAuthorization) {
 			return nil, fmt.Errorf("Signed headers cannot include the 'Authorization' header")
 		}
 		m[h] = true