diff --git a/spine-godot/build/build-v4.sh b/spine-godot/build/build-v4.sh
index 7ba3668dc6..eb985eec8f 100755
--- a/spine-godot/build/build-v4.sh
+++ b/spine-godot/build/build-v4.sh
@@ -102,7 +102,7 @@ else
 	if [ $mono == "true" ]; then
 		echo "Building C# glue and assemblies."
 		"./bin/$godot_exe_host" --headless --generate-mono-glue modules/mono/glue
-		./modules/mono/build_scripts/build_assemblies.py --godot-output-dir ./bin --push-nupkgs-local ../godot-nuget
+		python3 ./modules/mono/build_scripts/build_assemblies.py --godot-output-dir ./bin --push-nupkgs-local ../godot-nuget
 	fi
 	cp compile_commands.json ../build
 	if [ -f "bin/godot.linuxbsd.editor.x86_64$mono_extension" ]; then