diff --git a/utils/mnetftn/ftntomnet.c b/utils/mnetftn/ftntomnet.c
index 9c36357..5dc32eb 100644
--- a/utils/mnetftn/ftntomnet.c
+++ b/utils/mnetftn/ftntomnet.c
@@ -19,14 +19,14 @@ struct msgarea_t {
 };
 
 struct msg_t {
-    int area;
+    uint32_t area;
     char from[32];
     char to[32];
     char subject[64];
     uint32_t timedate;
-    int oaddr;
-    int daddr;
-    int type;
+    uint32_t oaddr;
+    uint32_t daddr;
+    uint32_t type;
     char reply[36];
 } __attribute__ ((packed));
 
diff --git a/utils/mnetftn/mnettoftn.c b/utils/mnetftn/mnettoftn.c
index 6bce4c6..7cd154d 100644
--- a/utils/mnetftn/mnettoftn.c
+++ b/utils/mnetftn/mnettoftn.c
@@ -28,14 +28,14 @@ struct msgarea_t {
 };
 
 struct msg_t {
-    int area;
+    uint32_t area;
     char from[32];
     char to[32];
     char subject[64];
     uint32_t timedate;
-    int oaddr;
-    int daddr;
-    int type;
+    uint32_t oaddr;
+    uint32_t daddr;
+    uint32_t type;
     char reply[36];
 } __attribute__ ((packed));