diff --git a/diff.c b/diff.c
index c4a669ffa8690f..5c12e3d4cd35f1 100644
--- a/diff.c
+++ b/diff.c
@@ -3867,6 +3867,10 @@ static void run_external_diff(const char *pgm,
 	argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
 	argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
 
+	if (one && one->should_munmap)
+		diff_free_filespec_data(one);
+	if (two && two->should_munmap)
+		diff_free_filespec_data(two);
 	if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
 		die(_("external diff died, stopping at %s"), name);