diff --git a/scripts/build_ffi.py b/scripts/build_ffi.py
index 82087b3..6807edf 100644
--- a/scripts/build_ffi.py
+++ b/scripts/build_ffi.py
@@ -1350,7 +1350,7 @@ def build_ffi(local_wolfssl, features):
         int wc_dilithium_import_public(const byte* in, word32 inLen, dilithium_key* key);
         int wc_dilithium_sign_ctx_msg(const byte* ctx, byte ctxLen, const byte* msg, word32 msgLen, byte* sig, word32* sigLen, dilithium_key* key, WC_RNG* rng);
         int wc_dilithium_sign_ctx_msg_with_seed(const byte* ctx, byte ctxLen, const byte* msg, word32 msgLen, byte* sig, word32* sigLen, dilithium_key* key, const byte* seed);
-        int wc_dilithium_verify_ctx_msg(const byte* sig, word32 sigLen, const byte* ctx, word32 ctxLen, const byte* msg, word32 msgLen, int* res, dilithium_key* key);
+        int wc_dilithium_verify_ctx_msg(const byte* sig, word32 sigLen, const byte* ctx, byte ctxLen, const byte* msg, word32 msgLen, int* res, dilithium_key* key);
         typedef dilithium_key MlDsaKey;
         int wc_MlDsaKey_GetPrivLen(MlDsaKey* key, int* len);
         int wc_MlDsaKey_GetPubLen(MlDsaKey* key, int* len);
diff --git a/wolfcrypt/ciphers.py b/wolfcrypt/ciphers.py
index b7b8c05..d66071e 100644
--- a/wolfcrypt/ciphers.py
+++ b/wolfcrypt/ciphers.py
@@ -2364,6 +2364,10 @@ def verify(self, signature: BytesOrStr, message: BytesOrStr, ctx: BytesOrStr | N
 
             if ctx is not None:
                 ctx_bytestype = t2b(ctx)
+                if len(ctx_bytestype) > 255:
+                    raise ValueError(
+                        f"context length {len(ctx_bytestype)} too large: must be 255 or less"
+                    )
                 ret = _lib.wc_dilithium_verify_ctx_msg(
                     sig_bytestype,
                     len(sig_bytestype),