diff --git a/src/nnn.c b/src/nnn.c
index e19b7afe..936b19f9 100644
--- a/src/nnn.c
+++ b/src/nnn.c
@@ -1335,21 +1335,23 @@ static char *bmtarget(const char *filepath, char *cwd, char *buf)
 }
 
 /* wraps the argument in single quotes so it can be safely fed to shell */
-static bool shell_escape(char *output, size_t outlen, const char *s)
+static ssize_t shell_escape(char *output, size_t outlen, const char *s)
 {
 	size_t n = xstrlen(s), w = 0;
 
-	if (s == output) {
-		DPRINTF_S("s == output");
-		return FALSE;
+	if (s == output || outlen < 3) {
+		errno = EINVAL;
+		return -1;
 	}
 
 	output[w++] = '\''; /* begin single quote */
 	for (size_t r = 0; r < n; ++r) {
 		/* potentially too big: 4 for the single quote case, 2 from
 		 * outside the loop */
-		if (w + 6 >= outlen)
-			return FALSE;
+		if (w + 6 >= outlen) {
+			errno = ENAMETOOLONG;
+			return -1;
+		}
 
 		switch (s[r]) {
 		/* the only thing that has special meaning inside single
@@ -1366,8 +1368,8 @@ static bool shell_escape(char *output, size_t outlen, const char *s)
 		}
 	}
 	output[w++] = '\''; /* end single quote */
-	output[w++] = '\0'; /* nul terminator */
-	return TRUE;
+	output[w]   = '\0'; /* nul terminator */
+	return w;
 }
 
 static bool set_tilde_in_path(char *path)
@@ -2841,7 +2843,7 @@ static void archive_selection(const char *cmd, const char *archive)
 
 static void write_lastdir(const char *curpath, const char *outfile)
 {
-	bool tilde = false;
+	bool tilde = false, ok = false;
 	if (!outfile)
 		xstrsncpy(cfgpath + xstrlen(cfgpath), "/.lastd", 8);
 	else
@@ -2850,15 +2852,14 @@ static void write_lastdir(const char *curpath, const char *outfile)
 	int fd = open(outfile
 			? (tilde ? g_buf : outfile)
 			: cfgpath, O_CREAT | O_WRONLY | O_TRUNC, S_IWUSR | S_IRUSR);
-
-	if (fd != -1 && shell_escape(g_buf, sizeof(g_buf), curpath)) {
-		if (write(fd, "cd ", 3) == 3) {
-			if (write(fd, g_buf, strlen(g_buf)) != (ssize_t)strlen(g_buf)) {
-				DPRINTF_S("write failed!");
-			}
-		}
+	if (fd >= 0) {
+		memcpy(g_buf, "cd ", 3);  // NOLINT
+		ssize_t l = shell_escape(g_buf + 3, sizeof(g_buf) - 3, curpath);
+		ok = l >= 0 && write(fd, g_buf, l + 3) == l + 3;
 		close(fd);
 	}
+	if (!ok)
+		errexit();
 }
 
 /*