diff --git a/internal/mock/grpc_server.go b/internal/mock/grpc_server.go
index d501abf9b357610d7998816bfd0ac5dce8b10a5d..66f6fd73b5e8fef4ba4fb68bc48ee9dd6b9096f7 100644
--- a/internal/mock/grpc_server.go
+++ b/internal/mock/grpc_server.go
@@ -95,7 +95,11 @@ func (s *binaryFileServer) FindBinaryFilesMetaData(_ context.Context, _ *pb.Grpc
 	return &pb.GrpcFindFilesResponse{}, nil
 }
 
-func (s *binaryFileServer) GetBinaryFileContent(_ *pb.GrpcGetBinaryFileDataRequest, stream pb.BinaryFileService_GetBinaryFileContentServer) error {
+func (s *binaryFileServer) GetBinaryFileContent(in *pb.GrpcGetBinaryFileDataRequest, stream pb.BinaryFileService_GetBinaryFileContentServer) error {
+	if in.FileId == "" {
+		return status.Error(codes.InvalidArgument, "FileId is missing")
+	}
+
 	fp := defaultFilePath
 	if testing.Testing() {
 		fp = testFilePath
@@ -117,9 +121,7 @@ func (s *binaryFileServer) GetBinaryFileContent(_ *pb.GrpcGetBinaryFileDataReque
 			return err
 		}
 
-		chunk := &pb.GrpcGetBinaryFileDataResponse{
-			FileContent: buffer[:bytesRead],
-		}
+		chunk := &pb.GrpcGetBinaryFileDataResponse{FileContent: buffer[:bytesRead]}
 		if err := stream.Send(chunk); err != nil {
 			return err
 		}
diff --git a/internal/server/grpc_router.go b/internal/server/grpc_router.go
index ba506dae05d69bd15d4035adff243222ca4bcef8..b34e99683913f3ec106188865044ccb2e5610240 100644
--- a/internal/server/grpc_router.go
+++ b/internal/server/grpc_router.go
@@ -195,7 +195,7 @@ func StartGrpcRouter() *grpc.Server {
 	}
 	logger.Info("gRPC router listening on port %d", conf.Grpc.Router.Port)
 
-	if err := s.Serve(lis); err != nil {
+	if err = s.Serve(lis); err != nil {
 		logger.Fatal("gRPC router failed to serve: %v", err)
 	}
 
diff --git a/internal/server/grpc_router_test.go b/internal/server/grpc_router_test.go
index 0f81f57990bc82fe7c69d694d6b28b0ff2796ba1..15e55208b8f2453452b766aaa308dc68061480e9 100644
--- a/internal/server/grpc_router_test.go
+++ b/internal/server/grpc_router_test.go
@@ -69,7 +69,7 @@ func TestStartGrpcRouter(t *testing.T) {
 		client, cleanUp := setUpGrpcRouterEnv()
 		defer cleanUp()
 
-		md := metadata.New(map[string]string{"x-grpc-address": "localhost"})
+		md := metadata.New(map[string]string{GrpcAddressMetadata: "localhost"})
 		ctx := metadata.NewOutgoingContext(context.Background(), md)
 		resp, err := client.FindRueckfragen(ctx, &pb.GrpcFindRueckfragenRequest{PostfachId: "testPostfachId"})
 
@@ -81,7 +81,7 @@ func TestStartGrpcRouter(t *testing.T) {
 		client, cleanUp := setUpGrpcRouterEnv()
 		defer cleanUp()
 
-		md := metadata.New(map[string]string{"x-grpc-address": "localhost"})
+		md := metadata.New(map[string]string{GrpcAddressMetadata: "localhost"})
 		ctx := metadata.NewOutgoingContext(context.Background(), md)
 		resp, err := client.FindRueckfragen(ctx, &pb.GrpcFindRueckfragenRequest{})
 
diff --git a/internal/server/handler.go b/internal/server/handler.go
index 88a294cdf54c903ed3df4276567772e69d9ce70c..f0e0e05bba211a950345a96fe551b2872fb48ae3 100644
--- a/internal/server/handler.go
+++ b/internal/server/handler.go
@@ -41,6 +41,7 @@ import (
 )
 
 const (
+	fileIdParam                 = "fileId"
 	fileFormKey                 = "file"
 	vorgangIdFormKey            = "vorgangId"
 	contentTypeHeaderKey        = "Content-Type"
@@ -195,7 +196,7 @@ func sendFileChunks(stream pb.BinaryFileService_UploadBinaryFileAsStreamClient,
 }
 
 func RegisterGetFileEndpoint(mux *runtime.ServeMux) {
-	err := mux.HandlePath("GET", "/api/v1/file/content/{fileId}", getFileHandler)
+	err := mux.HandlePath("GET", "/api/v1/file/content/{"+fileIdParam+"}", getFileHandler)
 
 	if err != nil {
 		logger.Fatal("failed to register get file endpoint: %v", err)
@@ -203,7 +204,7 @@ func RegisterGetFileEndpoint(mux *runtime.ServeMux) {
 }
 
 func getFileHandler(w http.ResponseWriter, r *http.Request, vars map[string]string) {
-	fileBuffer, err := fetchFileFromGrpc(r.Context(), vars["fileId"], r.Header.Get(GrpcAddressHeader))
+	fileBuffer, err := fetchFileFromGrpc(r.Context(), vars[fileIdParam], r.Header.Get(GrpcAddressHeader))
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
@@ -215,7 +216,7 @@ func getFileHandler(w http.ResponseWriter, r *http.Request, vars map[string]stri
 	}
 }
 
-func fetchFileFromGrpc(ctx context.Context, fileId, grpcAddress string) (*bytes.Buffer, error) {
+func fetchFileFromGrpc(ctx context.Context, fileId string, grpcAddress string) (*bytes.Buffer, error) {
 	var fileBuffer bytes.Buffer
 
 	target := GetGrpcServerUrl(grpcAddress, conf)
diff --git a/internal/server/handler_test.go b/internal/server/handler_test.go
index c2e6d3578e4ed10402ae7d18012b6db642cf20d0..8aa40f2fe72fc6a1a22db92dd3f43d6bfdd41f43 100644
--- a/internal/server/handler_test.go
+++ b/internal/server/handler_test.go
@@ -129,7 +129,6 @@ func TestRegisterBinaryFileEndpoints(t *testing.T) {
 
 func TestRegisterFileUploadEndpoint(t *testing.T) {
 	mock.SetUpGrpcServer()
-	SetUpGrpcRouter()
 	SetUpHttpGateway()
 
 	var requestBody bytes.Buffer
@@ -161,7 +160,6 @@ func TestRegisterFileUploadEndpoint(t *testing.T) {
 
 func TestRegisterGetFileEndpoint(t *testing.T) {
 	mock.SetUpGrpcServer()
-	SetUpGrpcRouter()
 	SetUpHttpGateway()
 
 	jsonData := []byte(``)