diff --git a/bin/tmuxifier b/bin/tmuxifier
index 7628ecf..624e0f9 100755
--- a/bin/tmuxifier
+++ b/bin/tmuxifier
@@ -27,7 +27,7 @@ case "$command" in
     command_path="$(command -v "tmuxifier-$command" || true)"
 
     # Attempt to resolve aliases
-    if [ -z $command_path ]; then
+    if [ -z "$command_path" ]; then
       resolved="$(tmuxifier-alias "$command")"
       if [ ! -z "$resolved" ]; then
         command_path="$(command -v "tmuxifier-$resolved" || true)"