diff --git a/bacnet-stack/ports/at91sam7s/dlmstp.c b/bacnet-stack/ports/at91sam7s/dlmstp.c
index e3935053..75570e78 100644
--- a/bacnet-stack/ports/at91sam7s/dlmstp.c
+++ b/bacnet-stack/ports/at91sam7s/dlmstp.c
@@ -334,9 +334,13 @@ static bool dlmstp_compare_data_expecting_reply(
     if (request.npdu_data.protocol_version != reply.npdu_data.protocol_version) {
         return false;
     }
+#if 0
+    /* the NDPU priority doesn't get passed through the stack, and
+       all outgoing messages have NORMAL priority */
     if (request.npdu_data.priority != reply.npdu_data.priority) {
         return false;
     }
+#endif
     if (!bacnet_address_same(&request.address, &reply.address)) {
         return false;
     }
diff --git a/bacnet-stack/ports/bdk-atxx4-mstp/dlmstp.c b/bacnet-stack/ports/bdk-atxx4-mstp/dlmstp.c
index c66d4a75..21222019 100644
--- a/bacnet-stack/ports/bdk-atxx4-mstp/dlmstp.c
+++ b/bacnet-stack/ports/bdk-atxx4-mstp/dlmstp.c
@@ -333,9 +333,13 @@ static bool dlmstp_compare_data_expecting_reply(
     if (request.npdu_data.protocol_version != reply.npdu_data.protocol_version) {
         return false;
     }
+#if 0
+    /* the NDPU priority doesn't get passed through the stack, and
+       all outgoing messages have NORMAL priority */
     if (request.npdu_data.priority != reply.npdu_data.priority) {
         return false;
     }
+#endif
     if (!bacnet_address_same(&request.address, &reply.address)) {
         return false;
     }
diff --git a/bacnet-stack/ports/linux/dlmstp.c b/bacnet-stack/ports/linux/dlmstp.c
index 70d5dbfc..de89b072 100644
--- a/bacnet-stack/ports/linux/dlmstp.c
+++ b/bacnet-stack/ports/linux/dlmstp.c
@@ -482,6 +482,9 @@ static bool dlmstp_compare_data_expecting_reply(
 #endif
         return false;
     }
+#if 0
+    /* the NDPU priority doesn't get passed through the stack, and
+       all outgoing messages have NORMAL priority */
     if (request.npdu_data.priority != reply.npdu_data.priority) {
 #if PRINT_ENABLED
         fprintf(stderr,
@@ -489,6 +492,7 @@ static bool dlmstp_compare_data_expecting_reply(
 #endif
         return false;
     }
+#endif
     if (!bacnet_address_same(&request.address, &reply.address)) {
 #if PRINT_ENABLED
         fprintf(stderr,
diff --git a/bacnet-stack/ports/linux/dlmstp_linux.c b/bacnet-stack/ports/linux/dlmstp_linux.c
index 679bbb7e..19912d8a 100644
--- a/bacnet-stack/ports/linux/dlmstp_linux.c
+++ b/bacnet-stack/ports/linux/dlmstp_linux.c
@@ -534,6 +534,9 @@ bool dlmstp_compare_data_expecting_reply(
 #endif
         return false;
     }
+#if 0
+    /* the NDPU priority doesn't get passed through the stack, and
+       all outgoing messages have NORMAL priority */
     if (request.npdu_data.priority != reply.npdu_data.priority) {
 #if PRINT_ENABLED
         fprintf(stderr,
@@ -541,6 +544,7 @@ bool dlmstp_compare_data_expecting_reply(
 #endif
         return false;
     }
+#endif
     if (!bacnet_address_same(&request.address, &reply.address)) {
 #if PRINT_ENABLED
         fprintf(stderr,
diff --git a/bacnet-stack/ports/pic18f6720/mstp.c b/bacnet-stack/ports/pic18f6720/mstp.c
index 802c9f7e..cff49540 100644
--- a/bacnet-stack/ports/pic18f6720/mstp.c
+++ b/bacnet-stack/ports/pic18f6720/mstp.c
@@ -650,9 +650,13 @@ static bool mstp_compare_data_expecting_reply(
     if (request.npdu_data.protocol_version != reply.npdu_data.protocol_version) {
         return false;
     }
+#if 0
+    /* the NDPU priority doesn't get passed through the stack, and
+       all outgoing messages have NORMAL priority */
     if (request.npdu_data.priority != reply.npdu_data.priority) {
         return false;
     }
+#endif
     if (!bacnet_address_same(&request.address, &reply.address)) {
         return false;
     }
diff --git a/bacnet-stack/ports/stm32f10x/dlmstp.c b/bacnet-stack/ports/stm32f10x/dlmstp.c
index b811df48..002cddc8 100644
--- a/bacnet-stack/ports/stm32f10x/dlmstp.c
+++ b/bacnet-stack/ports/stm32f10x/dlmstp.c
@@ -351,9 +351,13 @@ static bool dlmstp_compare_data_expecting_reply(
     if (request.npdu_data.protocol_version != reply.npdu_data.protocol_version) {
         return false;
     }
+#if 0
+    /* the NDPU priority doesn't get passed through the stack, and
+       all outgoing messages have NORMAL priority */
     if (request.npdu_data.priority != reply.npdu_data.priority) {
         return false;
     }
+#endif
     if (!bacnet_address_same(&request.address, &reply.address)) {
         return false;
     }
diff --git a/bacnet-stack/ports/win32/dlmstp-mm.c b/bacnet-stack/ports/win32/dlmstp-mm.c
index 223d6976..de3fc453 100644
--- a/bacnet-stack/ports/win32/dlmstp-mm.c
+++ b/bacnet-stack/ports/win32/dlmstp-mm.c
@@ -413,9 +413,13 @@ bool dlmstp_compare_data_expecting_reply(
     if (request.npdu_data.protocol_version != reply.npdu_data.protocol_version) {
         return false;
     }
+#if 0
+    /* the NDPU priority doesn't get passed through the stack, and
+       all outgoing messages have NORMAL priority */
     if (request.npdu_data.priority != reply.npdu_data.priority) {
         return false;
     }
+#endif
     if (!bacnet_address_same(&request.address, &reply.address)) {
         return false;
     }
diff --git a/bacnet-stack/ports/win32/dlmstp.c b/bacnet-stack/ports/win32/dlmstp.c
index d0b170a8..1fddac76 100644
--- a/bacnet-stack/ports/win32/dlmstp.c
+++ b/bacnet-stack/ports/win32/dlmstp.c
@@ -401,9 +401,13 @@ static bool dlmstp_compare_data_expecting_reply(
     if (request.npdu_data.protocol_version != reply.npdu_data.protocol_version) {
         return false;
     }
+#if 0
+    /* the NDPU priority doesn't get passed through the stack, and
+       all outgoing messages have NORMAL priority */
     if (request.npdu_data.priority != reply.npdu_data.priority) {
         return false;
     }
+#endif
     if (!bacnet_address_same(&request.address, &reply.address)) {
         return false;
     }
diff --git a/bacnet-stack/ports/xplained/dlmstp.c b/bacnet-stack/ports/xplained/dlmstp.c
index 3313a318..25996931 100644
--- a/bacnet-stack/ports/xplained/dlmstp.c
+++ b/bacnet-stack/ports/xplained/dlmstp.c
@@ -329,9 +329,13 @@ static bool dlmstp_compare_data_expecting_reply(uint8_t * request_pdu,
     if (request.npdu_data.protocol_version != reply.npdu_data.protocol_version) {
         return false;
     }
+#if 0
+    /* the NDPU priority doesn't get passed through the stack, and
+       all outgoing messages have NORMAL priority */
     if (request.npdu_data.priority != reply.npdu_data.priority) {
         return false;
     }
+#endif
     if (!bacnet_address_same(&request.address, &reply.address)) {
         return false;
     }