diff --git a/src/crypto.cpp b/src/crypto.cpp
index 36d006b518c9eae0e2a6f39485ecec65f5b18771..a0777c18ff8680fcf492815ceff16c77b89d2e76 100644
--- a/src/crypto.cpp
+++ b/src/crypto.cpp
@@ -120,7 +120,7 @@ bool aesKeySizeGood(size_t key_size)
 Blob aesEncrypt(const Blob& data, const Blob& key)
 {
     if (not aesKeySizeGood(key.size()))
-        throw DecryptError("Wrong key size: " + std::to_string(key.size()));
+        throw DecryptError("Wrong key size");
 
     Blob ret(data.size() + GCM_IV_SIZE + GCM_DIGEST_SIZE);
     {