diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 7147d64af2..8c49ce2544 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -2432,7 +2432,7 @@ if [[ -n ${ZSH_VERSION-} ]]; then
 				--*=*|*.) ;;
 				*) c="$c " ;;
 				esac
-				array+=("$c")
+				array[$#array+1]="$c"
 			done
 			compset -P '*[=:]'
 			compadd -Q -S '' -p "${2-}" -a -- array && _ret=0