diff --git a/src/basic/escape.c b/src/basic/escape.c
index 1cb7ced545..e04b435d5b 100644
--- a/src/basic/escape.c
+++ b/src/basic/escape.c
@@ -445,31 +445,30 @@ char* escape_non_printable_full(const char *str, size_t console_width, XEscapeFl
 }
 
 char* octescape(const char *s, size_t len) {
-        char *r, *t;
-        const char *f;
+        char *buf, *t;
 
-        /* Escapes all chars in bad, in addition to \ and " chars,
-         * in \nnn style escaping. */
+        /* Escapes all chars in bad, in addition to \ and " chars, in \nnn style escaping. */
 
-        r = new(char, len * 4 + 1);
-        if (!r)
+        assert(s || len == 0);
+
+        t = buf = new(char, len * 4 + 1);
+        if (!buf)
                 return NULL;
 
-        for (f = s, t = r; f < s + len; f++) {
+        for (size_t i = 0; i < len; i++) {
+                uint8_t u = (uint8_t) s[i];
 
-                if (*f < ' ' || *f >= 127 || IN_SET(*f, '\\', '"')) {
+                if (u < ' ' || u >= 127 || IN_SET(u, '\\', '"')) {
                         *(t++) = '\\';
-                        *(t++) = '0' + (*f >> 6);
-                        *(t++) = '0' + ((*f >> 3) & 8);
-                        *(t++) = '0' + (*f & 8);
+                        *(t++) = '0' + (u >> 6);
+                        *(t++) = '0' + ((u >> 3) & 7);
+                        *(t++) = '0' + (u & 7);
                 } else
-                        *(t++) = *f;
+                        *(t++) = u;
         }
 
         *t = 0;
-
-        return r;
-
+        return buf;
 }
 
 static char* strcpy_backslash_escaped(char *t, const char *s, const char *bad) {
diff --git a/src/test/test-escape.c b/src/test/test-escape.c
index da19272624..de82020d5f 100644
--- a/src/test/test-escape.c
+++ b/src/test/test-escape.c
@@ -219,4 +219,20 @@ TEST(quote_command_line) {
                                     "true \"\\$dollar\"");
 }
 
+static void test_octescape_one(const char *s, const char *expected) {
+        _cleanup_free_ char *ret;
+
+        assert_se(ret = octescape(s, strlen_ptr(s)));
+        log_debug("octescape(\"%s\") → \"%s\" (expected: \"%s\")", strnull(s), ret, expected);
+        assert_se(streq(ret, expected));
+}
+
+TEST(octescape) {
+        test_octescape_one(NULL, "");
+        test_octescape_one("", "");
+        test_octescape_one("foo", "foo");
+        test_octescape_one("\"\\\"", "\\042\\134\\042");
+        test_octescape_one("\123\213\222", "\123\\213\\222");
+}
+
 DEFINE_TEST_MAIN(LOG_DEBUG);
diff --git a/test/fuzz/fuzz-resource-record/clusterfuzz-testcase-minimized-fuzz-resource-record-5844226627993600 b/test/fuzz/fuzz-resource-record/clusterfuzz-testcase-minimized-fuzz-resource-record-5844226627993600
new file mode 100644
index 0000000000..13778bf23b
Binary files /dev/null and b/test/fuzz/fuzz-resource-record/clusterfuzz-testcase-minimized-fuzz-resource-record-5844226627993600 differ