diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2022-09-26-16-46-54.gh-issue-96670.-n9hqb.rst b/Misc/NEWS.d/next/Core_and_Builtins/2022-09-26-16-46-54.gh-issue-96670.-n9hqb.rst
new file mode 100644
index 00000000000000..20371fb3458ecc
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2022-09-26-16-46-54.gh-issue-96670.-n9hqb.rst
@@ -0,0 +1 @@
+Fix interpreter crash when a string literal contains a null character.
diff --git a/Parser/string_parser.c b/Parser/string_parser.c
index 5df7ae8bec04b2..81d5001f3651da 100644
--- a/Parser/string_parser.c
+++ b/Parser/string_parser.c
@@ -249,12 +249,18 @@ _PyPegen_decode_string(Parser *p, int raw, const char *s, size_t len, Token *t)
 PyObject *
 _PyPegen_parse_string(Parser *p, Token *t)
 {
-    const char *s = PyBytes_AsString(t->bytes);
-    if (s == NULL) {
+    char *s;
+    Py_ssize_t len;
+
+    if (PyBytes_AsStringAndSize(t->bytes, &s, &len)) {
+        return NULL;
+    }
+
+    if (len > INT_MAX) {
+        PyErr_SetString(PyExc_OverflowError, "string to parse is too long");
         return NULL;
     }
 
-    size_t len;
     int quote = Py_CHARMASK(*s);
     int bytesmode = 0;
     int rawmode = 0;
@@ -263,13 +269,16 @@ _PyPegen_parse_string(Parser *p, Token *t)
         while (!bytesmode || !rawmode) {
             if (quote == 'b' || quote == 'B') {
                 quote =(unsigned char)*++s;
+                len--;
                 bytesmode = 1;
             }
             else if (quote == 'u' || quote == 'U') {
                 quote = (unsigned char)*++s;
+                len--;
             }
             else if (quote == 'r' || quote == 'R') {
                 quote = (unsigned char)*++s;
+                len--;
                 rawmode = 1;
             }
             else {
@@ -285,15 +294,11 @@ _PyPegen_parse_string(Parser *p, Token *t)
 
     /* Skip the leading quote char. */
     s++;
-    len = strlen(s);
+    len--;
     // gh-120155: 's' contains at least the trailing quote,
     // so the code '--len' below is safe.
     assert(len >= 1);
 
-    if (len > INT_MAX) {
-        PyErr_SetString(PyExc_OverflowError, "string to parse is too long");
-        return NULL;
-    }
     if (s[--len] != quote) {
         /* Last quote char must match the first. */
         PyErr_BadInternalCall();