diff --git a/admin/next.config.js b/admin/next.config.js
index 8a029e9..0898b94 100644
--- a/admin/next.config.js
+++ b/admin/next.config.js
@@ -6,8 +6,8 @@ module.exports = withCSS({
   async rewrites() {
     return [
       {
-        source: "/api/:path",
-        destination: "http://localhost:8080/api/:path", // Matched parameters can be used in the destination
+        source: "/api/:path/",
+        destination: "http://localhost:8080/api/:path/",
       },
     ];
   },
diff --git a/admin/src/lib/graphql.ts b/admin/src/lib/graphql.ts
index ada1469..3863d71 100644
--- a/admin/src/lib/graphql.ts
+++ b/admin/src/lib/graphql.ts
@@ -8,7 +8,7 @@ function createApolloClient() {
   return new ApolloClient({
     ssrMode: typeof window === "undefined",
     link: new HttpLink({
-      uri: "/api/graphql",
+      uri: "/api/graphql/",
     }),
     cache: new InMemoryCache({
       typePolicies: {
diff --git a/cmd/hetty/main.go b/cmd/hetty/main.go
index e329d76..7224cd8 100644
--- a/cmd/hetty/main.go
+++ b/cmd/hetty/main.go
@@ -81,11 +81,11 @@ func main() {
 		hostname, _ := os.Hostname()
 		host, _, _ := net.SplitHostPort(req.Host)
 		return strings.EqualFold(host, hostname) || (req.Host == "hetty.proxy" || req.Host == "localhost:8080")
-	}).Subrouter()
+	}).Subrouter().StrictSlash(true)
 
 	// GraphQL server.
-	adminRouter.Path("/api/playground").Handler(playground.Handler("GraphQL Playground", "/api/graphql"))
-	adminRouter.Path("/api/graphql").Handler(handler.NewDefaultServer(api.NewExecutableSchema(api.Config{Resolvers: &api.Resolver{
+	adminRouter.Path("/api/playground/").Handler(playground.Handler("GraphQL Playground", "/api/graphql/"))
+	adminRouter.Path("/api/graphql/").Handler(handler.NewDefaultServer(api.NewExecutableSchema(api.Config{Resolvers: &api.Resolver{
 		RequestLogService: reqLogService,
 	}})))