diff --git a/src/libcharon/plugins/tnccs_20/messages/pb_experimental_msg.c b/src/libcharon/plugins/tnccs_20/messages/pb_experimental_msg.c
index 6384703d4..7dfba136f 100644
--- a/src/libcharon/plugins/tnccs_20/messages/pb_experimental_msg.c
+++ b/src/libcharon/plugins/tnccs_20/messages/pb_experimental_msg.c
@@ -57,7 +57,7 @@ METHOD(pb_tnc_msg_t, build, void,
 }
 
 METHOD(pb_tnc_msg_t, process, status_t,
-	private_pb_experimental_msg_t *this, size_t *offset)
+	private_pb_experimental_msg_t *this, u_int32_t *offset)
 {
 	return SUCCESS;
 }
diff --git a/src/libcharon/plugins/tnccs_20/messages/pb_remediation_parameters_msg.c b/src/libcharon/plugins/tnccs_20/messages/pb_remediation_parameters_msg.c
index 6a8bce0d0..79381a7b1 100644
--- a/src/libcharon/plugins/tnccs_20/messages/pb_remediation_parameters_msg.c
+++ b/src/libcharon/plugins/tnccs_20/messages/pb_remediation_parameters_msg.c
@@ -122,7 +122,7 @@ METHOD(pb_tnc_msg_t, build, void,
 }
 
 METHOD(pb_tnc_msg_t, process, status_t,
-	private_pb_remediation_parameters_msg_t *this, size_t *offset)
+	private_pb_remediation_parameters_msg_t *this, u_int32_t *offset)
 {
 	tls_reader_t *reader;