diff --git a/install.sh b/install.sh
index ae067f7..a98aaab 100644
--- a/install.sh
+++ b/install.sh
@@ -1,12 +1,12 @@
 #!/bin/bash
 
 check_command() {
-    command -v $1 >/dev/null 2>&1
+    command -v "$1" >/dev/null 2>&1
 }
 
 check_version() {
     act_runner_version=$(act_runner -v | grep -o 'v[0-9]\+\.[0-9]\+\.[0-9]\+')
-    echo $act_runner_version
+    echo "$act_runner_version"
 }
 
 # Ensure jq is installed (attempt auto-install on common distros)
@@ -59,7 +59,7 @@ fi
 
 required_commands=("curl" "jq" "wget" "unxz" "sha256sum")
 for cmd in "${required_commands[@]}"; do
-    if ! check_command $cmd; then
+    if ! check_command "$cmd"; then
         echo "Error: '$cmd' command not found. Please make sure all required commands are installed."
         exit 1
     fi
@@ -71,21 +71,21 @@ if [ "$arch" = "x86_64" ]; then
 fi
 
 json=$(curl -s https://gitea.com/api/v1/repos/gitea/act_runner/releases/latest)
-latest_version=$(echo $json | jq -r '.tag_name')
-url_checksum=$(echo $json | jq -r '.assets[] | select(.name | contains("linux-'$arch'") and contains(".xz.sha256")) | .browser_download_url')
-url_binary=$(echo $json | jq -r '.assets[] | select(.name | contains("linux-'$arch'") and contains(".xz")) | .browser_download_url')
-checksum_filename=$(basename $url_checksum)
-filename=$(basename $url_binary)
+latest_version=$(echo "$json" | jq -r '.tag_name')
+url_checksum=$(echo "$json" | jq -r '.assets[] | select(.name | contains("linux-'"$arch"'") and contains(".xz.sha256")) | .browser_download_url')
+url_binary=$(echo "$json" | jq -r '.assets[] | select(.name | contains("linux-'"$arch"'") and contains(".xz")) | .browser_download_url')
+checksum_filename=$(basename "$url_checksum")
+filename=$(basename "$url_binary")
 
 if [ -z "$current_version" ] || [ "$current_version" != "$latest_version" ]; then
     echo "Updating act_runner to version: $latest_version"
-    wget $url_binary
-    wget $url_checksum
-    sha256sum -c $checksum_filename
-    rm $checksum_filename
-    unxz $filename
-    filename=$(echo $filename | sed 's/\.xz$//')
-    mv $filename '/usr/local/bin/act_runner'
+    wget "$url_binary"
+    wget "$url_checksum"
+    sha256sum -c "$checksum_filename"
+    rm "$checksum_filename"
+    unxz "$filename"
+    filename=${filename%.xz}
+    mv "$filename" '/usr/local/bin/act_runner'
     chmod +x /usr/local/bin/act_runner
     echo "Update completed."
 else