diff --git a/.github/workflows/spine-godot-extension-v4-all.yml b/.github/workflows/spine-godot-extension-v4-all.yml
index 560e37bc0..4e8403346 100644
--- a/.github/workflows/spine-godot-extension-v4-all.yml
+++ b/.github/workflows/spine-godot-extension-v4-all.yml
@@ -14,7 +14,7 @@ jobs:
       matrix:
         version:
           [
-            {"tag": "4.5.1-stable", "version": "4.5.1.stable", "dev": false},
+            {"tag": "4.6.1-stable", "version": "4.6.1.stable", "dev": false},
           ]
     uses: ./.github/workflows/spine-godot-extension-v4.yml
     with:
diff --git a/spine-godot/build/setup-extension.sh b/spine-godot/build/setup-extension.sh
index 29e68e83b..619e73a0b 100755
--- a/spine-godot/build/setup-extension.sh
+++ b/spine-godot/build/setup-extension.sh
@@ -35,6 +35,11 @@ fi
 
 godot_cpp_branch=$(echo $godot_branch | cut -d. -f1-2 | cut -d- -f1)
 
+if ! git ls-remote --exit-code --heads $godot_cpp_repo $godot_cpp_branch > /dev/null 2>&1; then
+    echo "godot-cpp branch '$godot_cpp_branch' not found, falling back to 'master'"
+    godot_cpp_branch="master"
+fi
+
 cpus=2
 if [ "$OSTYPE" == "msys" ]; then
 	cpus=$NUMBER_OF_PROCESSORS