diff --git a/src/crypto_impl.c b/src/crypto_impl.c
index 12fefb82..1e559eea 100644
--- a/src/crypto_impl.c
+++ b/src/crypto_impl.c
@@ -885,12 +885,12 @@ static int sqlcipher_cipher_ctx_key_derive(codec_ctx *ctx, cipher_ctx *c_ctx) {
       if(ctx->read_ctx->provider->random(ctx->read_ctx->provider_ctx, ctx->kdf_salt, FILE_HEADER_SZ) != SQLITE_OK) return SQLITE_ERROR;
       ctx->need_kdf_salt = 0;
     }
-    if (c_ctx->pass_sz == ((c_ctx->key_sz * 2) + 3) && sqlite3StrNICmp((const char *)c_ctx->pass ,"x'", 2) == 0) { 
+    if (c_ctx->pass_sz == ((c_ctx->key_sz * 2) + 3) && sqlite3StrNICmp((const char *)c_ctx->pass ,"x'", 2) == 0 && cipher_isHex(c_ctx->pass + 2, c_ctx->key_sz * 2)) { 
       int n = c_ctx->pass_sz - 3; /* adjust for leading x' and tailing ' */
       const unsigned char *z = c_ctx->pass + 2; /* adjust lead offset of x' */
       CODEC_TRACE(("cipher_ctx_key_derive: using raw key from hex\n")); 
       cipher_hex2bin(z, n, c_ctx->key);
-    } else if (c_ctx->pass_sz == (((c_ctx->key_sz + ctx->kdf_salt_sz) * 2) + 3) && sqlite3StrNICmp((const char *)c_ctx->pass ,"x'", 2) == 0) { 
+    } else if (c_ctx->pass_sz == (((c_ctx->key_sz + ctx->kdf_salt_sz) * 2) + 3) && sqlite3StrNICmp((const char *)c_ctx->pass ,"x'", 2) == 0 && cipher_isHex(c_ctx->pass + 2, (c_ctx->key_sz + ctx->kdf_salt_sz) * 2)) { 
       const unsigned char *z = c_ctx->pass + 2; /* adjust lead offset of x' */
       CODEC_TRACE(("cipher_ctx_key_derive: using raw key from hex\n")); 
       cipher_hex2bin(z, (c_ctx->key_sz * 2), c_ctx->key);