diff --git a/server/core/buffer.cc b/server/core/buffer.cc
index f49e95653..f870c838d 100644
--- a/server/core/buffer.cc
+++ b/server/core/buffer.cc
@@ -795,6 +795,7 @@ gwbuf_make_contiguous(GWBUF *orig)
 
     if (orig == NULL)
     {
+        ss_info_dassert(!true, "gwbuf_make_contiguous: NULL buffer");
         return NULL;
     }
     if (orig->next == NULL)
diff --git a/server/core/modutil.cc b/server/core/modutil.cc
index 527e64ae7..ad1bdde80 100644
--- a/server/core/modutil.cc
+++ b/server/core/modutil.cc
@@ -485,6 +485,17 @@ int modutil_send_mysql_err_packet(DCB        *dcb,
     return dcb->func.write(dcb, buf);
 }
 
+// Helper function for debug assertions
+static bool only_one_packet(GWBUF* buffer)
+{
+    ss_dassert(buffer);
+    uint8_t header[4] = {};
+    gwbuf_copy_data(buffer, 0, MYSQL_HEADER_LEN, header);
+    size_t packet_len = gw_mysql_get_byte3(header);
+    size_t buffer_len = gwbuf_length(buffer);
+    return packet_len + MYSQL_HEADER_LEN == buffer_len;
+}
+
 /**
  * Return the first packet from a buffer.
  *
@@ -531,6 +542,7 @@ GWBUF* modutil_get_next_MySQL_packet(GWBUF** p_readbuf)
         }
     }
 
+    ss_dassert(!packet || only_one_packet(packet));
     return packet;
 }
 
diff --git a/server/modules/protocol/MySQL/mariadbclient/mysql_client.cc b/server/modules/protocol/MySQL/mariadbclient/mysql_client.cc
index e633939ed..915b37d71 100644
--- a/server/modules/protocol/MySQL/mariadbclient/mysql_client.cc
+++ b/server/modules/protocol/MySQL/mariadbclient/mysql_client.cc
@@ -1576,17 +1576,6 @@ static bool reauthenticate_client(MXS_SESSION* session, GWBUF* packetbuf)
     return rval;
 }
 
-// Helper function for debug assertions
-static bool only_one_packet(GWBUF* buffer)
-{
-    ss_dassert(buffer);
-    uint8_t header[4] = {};
-    gwbuf_copy_data(buffer, 0, MYSQL_HEADER_LEN, header);
-    size_t packet_len = gw_mysql_get_byte3(header);
-    size_t buffer_len = gwbuf_length(buffer);
-    return packet_len + MYSQL_HEADER_LEN == buffer_len;
-}
-
 /**
  * Detect if buffer includes partial mysql packet or multiple packets.
  * Store partial packet to dcb_readqueue. Send complete packets one by one
@@ -1616,7 +1605,6 @@ static int route_by_statement(MXS_SESSION* session, uint64_t capabilities, GWBUF
 
         if (packetbuf != NULL)
         {
-            ss_dassert(only_one_packet(packetbuf));
             CHK_GWBUF(packetbuf);
             MySQLProtocol* proto = (MySQLProtocol*)session->client_dcb->protocol;