diff --git a/sway/commands/workspace.c b/sway/commands/workspace.c
index b911b2f61..a8a2f53b6 100644
--- a/sway/commands/workspace.c
+++ b/sway/commands/workspace.c
@@ -140,7 +140,10 @@ struct cmd_results *cmd_workspace(int argc, char **argv) {
 			break;
 		}
 	}
-	if (output_location >= 0) {
+	if (output_location == 0) {
+		return cmd_results_new(CMD_INVALID, "Expected 'workspace "
+				"<name> output <output>'");
+	} else if (output_location > 0) {
 		if ((error = checkarg(argc, "workspace", EXPECTED_AT_LEAST,
 						output_location + 2))) {
 			return error;