diff --git a/templates/dart/lib/src/client_browser.dart.twig b/templates/dart/lib/src/client_browser.dart.twig
index 05e646ce0..8481238e2 100644
--- a/templates/dart/lib/src/client_browser.dart.twig
+++ b/templates/dart/lib/src/client_browser.dart.twig
@@ -122,7 +122,7 @@ class ClientBrowser extends ClientBase with ClientMixin {
       try {
         res = await call(
           HttpMethod.get,
-          path: path + '/' + params[idParamName],
+          path: '$path/${params[idParamName]}',
           headers: headers,
         );
         final int chunksUploaded = res.data['chunksUploaded'] as int;
diff --git a/templates/dart/lib/src/client_io.dart.twig b/templates/dart/lib/src/client_io.dart.twig
index 952e361f5..260ec3d20 100644
--- a/templates/dart/lib/src/client_io.dart.twig
+++ b/templates/dart/lib/src/client_io.dart.twig
@@ -143,7 +143,7 @@ class ClientIO extends ClientBase with ClientMixin {
       try {
         res = await call(
           HttpMethod.get,
-          path: path + '/' + params[idParamName],
+          path: '$path/${params[idParamName]}',
           headers: headers,
         );
         final int chunksUploaded = res.data['chunksUploaded'] as int;
diff --git a/templates/flutter/lib/src/client_browser.dart.twig b/templates/flutter/lib/src/client_browser.dart.twig
index 2bce9adc5..e81c61ea9 100644
--- a/templates/flutter/lib/src/client_browser.dart.twig
+++ b/templates/flutter/lib/src/client_browser.dart.twig
@@ -150,7 +150,7 @@ class ClientBrowser extends ClientBase with ClientMixin {
       try {
         res = await call(
           HttpMethod.get,
-          path: path + '/' + params[idParamName],
+          path: '$path/${params[idParamName]}',
           headers: headers,
         );
         final int chunksUploaded = res.data['chunksUploaded'] as int;
@@ -243,7 +243,7 @@ class ClientBrowser extends ClientBase with ClientMixin {
   Future webAuth(Uri url, {String? callbackUrlScheme}) {
     return FlutterWebAuth2.authenticate(
       url: url.toString(),
-      callbackUrlScheme: "{{spec.title | caseLower}}-callback-" + config['project']!,
+      callbackUrlScheme: "{{spec.title | caseLower}}-callback-${config['project']!}",
       options: const FlutterWebAuth2Options(useWebview: false),
     );
   }
diff --git a/templates/flutter/lib/src/client_io.dart.twig b/templates/flutter/lib/src/client_io.dart.twig
index f2ee28447..314a1c6bb 100644
--- a/templates/flutter/lib/src/client_io.dart.twig
+++ b/templates/flutter/lib/src/client_io.dart.twig
@@ -272,7 +272,7 @@ class ClientIO extends ClientBase with ClientMixin {
       try {
         res = await call(
           HttpMethod.get,
-          path: path + '/' + params[idParamName],
+          path: '$path/${params[idParamName]}',
           headers: headers,
         );
         final int chunksUploaded = res.data['chunksUploaded'] as int;
@@ -333,7 +333,7 @@ class ClientIO extends ClientBase with ClientMixin {
       url: url.toString(),
       callbackUrlScheme: callbackUrlScheme != null && _customSchemeAllowed
           ? callbackUrlScheme
-          : "{{spec.title | caseLower}}-callback-" + config['project']!,
+          : "{{spec.title | caseLower}}-callback-${config['project']!}",
       options: const FlutterWebAuth2Options(
         intentFlags: ephemeralIntentFlags,
         useWebview: false,