diff --git a/epan/dissectors/packet-ntlmssp.c b/epan/dissectors/packet-ntlmssp.c
index cdfb765b63..2b37091fb4 100644
--- a/epan/dissectors/packet-ntlmssp.c
+++ b/epan/dissectors/packet-ntlmssp.c
@@ -2291,7 +2291,7 @@ decrypt_verifier(tvbuff_t *tvb, int offset, guint32 encrypted_block_length,
 
       /* Setup the buffer to decrypt to */
       tvb_memcpy(tvb, packet_ntlmssp_info->verifier,
-                 offset, encrypted_block_length);
+                 offset, MIN(encrypted_block_length, sizeof(packet_ntlmssp_info->verifier)));
 
       /*if (!(NTLMSSP_NEGOTIATE_KEY_EXCH & packet_ntlmssp_info->flags)) {*/
       if (conv_ntlmssp_info->flags & NTLMSSP_NEGOTIATE_EXTENDED_SECURITY) {