diff --git a/modules/openapi-generator/src/main/resources/go/client.mustache b/modules/openapi-generator/src/main/resources/go/client.mustache
index ddec54229a31..ee6ba43f5741 100644
--- a/modules/openapi-generator/src/main/resources/go/client.mustache
+++ b/modules/openapi-generator/src/main/resources/go/client.mustache
@@ -427,8 +427,9 @@ func CacheExpires(r *http.Response) time.Time {
 		lifetime, err := time.ParseDuration(maxAge + "s")
 		if err != nil {
 			expires = now
+		} else {
+			expires = now.Add(lifetime)
 		}
-		expires = now.Add(lifetime)
 	} else {
 		expiresHeader := r.Header.Get("Expires")
 		if expiresHeader != "" {
diff --git a/samples/client/petstore/go/go-petstore/client.go b/samples/client/petstore/go/go-petstore/client.go
index c3908518e9e9..383830e8f436 100644
--- a/samples/client/petstore/go/go-petstore/client.go
+++ b/samples/client/petstore/go/go-petstore/client.go
@@ -438,8 +438,9 @@ func CacheExpires(r *http.Response) time.Time {
 		lifetime, err := time.ParseDuration(maxAge + "s")
 		if err != nil {
 			expires = now
+		} else {
+			expires = now.Add(lifetime)
 		}
-		expires = now.Add(lifetime)
 	} else {
 		expiresHeader := r.Header.Get("Expires")
 		if expiresHeader != "" {