diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index a334671..0c7456f 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -107,7 +107,7 @@ jobs:
 
       - name: Upload artifacts
         if: ${{ ( github.event_name == 'push' && github.ref == 'refs/heads/master' ) || github.event.inputs.create_release == 'true' }}
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           path: |
             rwkv-${{ env.BRANCH_NAME }}-${{ steps.commit.outputs.short }}-bin-${{ steps.system-info.outputs.OS_TYPE }}-${{ steps.system-info.outputs.OS_NAME }}-${{ steps.system-info.outputs.OS_VERSION }}-${{ steps.system-info.outputs.CPU_ARCH }}.zip
@@ -165,7 +165,7 @@ jobs:
 
       - name: Upload artifacts
         if: ${{ ( github.event_name == 'push' && github.ref == 'refs/heads/master' ) || github.event.inputs.create_release == 'true' }}
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           path: |
             rwkv-${{ env.BRANCH_NAME }}-${{ steps.commit.outputs.short }}-bin-${{ steps.system-info.outputs.OS_TYPE }}-${{ steps.system-info.outputs.OS_NAME }}-${{ steps.system-info.outputs.OS_VERSION }}-${{ steps.system-info.outputs.CPU_ARCH }}.zip
@@ -296,7 +296,7 @@ jobs:
 
       - name: Upload artifacts
         if: ${{ ( github.event_name == 'push' && github.ref == 'refs/heads/master' ) || github.event.inputs.create_release == 'true' }}
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           path: |
             rwkv-${{ env.BRANCH_NAME }}-${{ steps.commit.outputs.short }}-bin-win-${{ matrix.build }}-x64.zip
@@ -317,7 +317,7 @@ jobs:
     steps:
       - name: Download artifacts
         id: download-artifact
-        uses: actions/download-artifact@v3
+        uses: actions/download-artifact@v4
 
       - name: Get commit hash
         id: commit
diff --git a/rwkv.cpp b/rwkv.cpp
index 5ccc97b..19a78c4 100644
--- a/rwkv.cpp
+++ b/rwkv.cpp
@@ -80,7 +80,7 @@ struct rwkv_context * rwkv_init_from_file(const char * file_path, const uint32_t
     ctx->n_threads = n_threads;
 
     if (n_gpu_layers) {
-        ggml_backend_t backend;
+        ggml_backend_t backend = nullptr;
 
 #ifdef GGML_USE_CUDA
         backend = ggml_backend_cuda_init(0);
@@ -97,9 +97,9 @@ struct rwkv_context * rwkv_init_from_file(const char * file_path, const uint32_t
         RWKV_ENSURE_OR_NULL(backend);
         ggml_backend_blas_set_n_threads(backend, ctx->n_threads);
 #endif
-        RWKV_ENSURE_OR_NULL(backend);
-
-        ctx->model->backends.push_back(backend);
+        if (backend != nullptr) {
+            ctx->model->backends.push_back(backend);
+        }
     }
 
     ggml_backend_t cpu_backend = ggml_backend_cpu_init();