diff --git a/src/ua_securechannel_crypto.c b/src/ua_securechannel_crypto.c
index 2b55eaff3c2..cc5e135fc8d 100644
--- a/src/ua_securechannel_crypto.c
+++ b/src/ua_securechannel_crypto.c
@@ -262,7 +262,7 @@ padChunk(UA_SecureChannel *channel, const UA_SecurityPolicyCryptoModule *cm,
     /* Write the padding. This is <= because the paddingSize byte also has to be
      * written */
     UA_Byte paddingByte = (UA_Byte)paddingLength;
-    for(UA_UInt16 i = 0; i <= paddingLength; ++i) {
+    for(size_t i = 0; i <= paddingLength; ++i) {
         **pos = paddingByte;
         ++*pos;
     }