diff --git a/setup-bazel/action.yml b/setup-bazel/action.yml
index 16cf2af..ef48c1d 100644
--- a/setup-bazel/action.yml
+++ b/setup-bazel/action.yml
@@ -17,6 +17,19 @@ inputs:
 runs:
   using: 'composite'
   steps:
+    - name: Fix MTU size for Proxmox/Docker network compatibility
+      shell: bash
+      run: |
+        DEFAULT_INTERFACE=$(ip route show | grep default | awk '{print $5}')
+        if [ -n "$DEFAULT_INTERFACE" ]; then
+          echo "Setting MTU of $DEFAULT_INTERFACE to 1400..."
+          if [ "$(id -u)" -eq 0 ]; then
+            ip link set dev "$DEFAULT_INTERFACE" mtu 1400 || true
+          else
+            sudo ip link set dev "$DEFAULT_INTERFACE" mtu 1400 || true
+          fi
+        fi
+
     - name: Setup Node
       uses: actions/setup-node@v4
       with: