diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index b1a3942..3d0b909 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -25,13 +25,6 @@ jobs:
     steps:
     - uses: actions/checkout@v4
 
-    - name: Install Bash 5 on macOS
-      if: runner.os == 'macOS'
-      run: |
-        /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"
-        brew install bash
-        bash --version
-
     - uses: sigoden/install-binary@v1
       with:
         repo: sigoden/argc
diff --git a/scripts/bin.sh b/scripts/bin.sh
index d169a07..807343a 100755
--- a/scripts/bin.sh
+++ b/scripts/bin.sh
@@ -15,7 +15,7 @@ else
     func_data="$1"
 fi
 if [[ "$func_name" == *.sh ]]; then
-    func_name="${func_name::-3}"
+    func_name="${func_name:0:$((${#func_name}-3))}"
 fi
 
 export LLM_FUNCTION_NAME="$func_name"