diff --git a/plugins/git-commit/git-commit.plugin.zsh b/plugins/git-commit/git-commit.plugin.zsh
index 121ae59de..c4df77c80 100644
--- a/plugins/git-commit/git-commit.plugin.zsh
+++ b/plugins/git-commit/git-commit.plugin.zsh
@@ -46,7 +46,7 @@ case $1 in
     shift 1
     ;;
   * )
-    _message+=" $1"
+    _message="${_message} $1"
     shift 1
     ;;
 esac