diff --git a/contrib/completion/git-prompt.sh b/contrib/completion/git-prompt.sh
index 5330e769a7..ebf2e30d68 100644
--- a/contrib/completion/git-prompt.sh
+++ b/contrib/completion/git-prompt.sh
@@ -137,7 +137,9 @@ __git_ps1_show_upstream ()
 			upstream_type=svn+git # default upstream type is SVN if available, else git
 			;;
 		esac
-	done <<< "$output"
+	done <<-OUTPUT
+		$output
+	OUTPUT
 
 	# parse configuration values
 	local option