diff --git a/Modules/_sha3/sha3module.c b/Modules/_sha3/sha3module.c
index 46c1ff1..b737363 100644
--- a/Modules/_sha3/sha3module.c
+++ b/Modules/_sha3/sha3module.c
@@ -589,6 +589,10 @@
     int res;
     PyObject *result = NULL;
 
+    if (digestlen >= (1 << 29)) {
+        PyErr_SetString(PyExc_ValueError, "length is too large");
+        return NULL;
+    }
     /* ExtractLane needs at least SHA3_MAX_DIGESTSIZE + SHA3_LANESIZE and
      * SHA3_LANESIZE extra space.
      */