diff --git a/wiretap/ngsniffer.c b/wiretap/ngsniffer.c
index a0986615a4..5cd02106cb 100644
--- a/wiretap/ngsniffer.c
+++ b/wiretap/ngsniffer.c
@@ -2497,7 +2497,7 @@ ng_file_read(void *buffer, size_t elementsize, size_t numelements, wtap *wth,
 	copybytes -= bytes_to_copy;
 	copied_bytes += bytes_to_copy;
 	outbuffer += bytes_to_copy;
-	comp_stream->nextout += bytes_to_copy;
+	comp_stream->nextout += (int) bytes_to_copy;
 	comp_stream->uncomp_offset += bytes_to_copy;
     }
     return copied_bytes;
diff --git a/wiretap/toshiba.c b/wiretap/toshiba.c
index a6d67900fe..de1ecc28da 100644
--- a/wiretap/toshiba.c
+++ b/wiretap/toshiba.c
@@ -177,7 +177,7 @@ static gboolean toshiba_check_file_type(wtap *wth, int *err)
 	for (line = 0; line < TOSHIBA_HEADER_LINES_TO_CHECK; line++) {
 		if (file_gets(buf, TOSHIBA_LINE_LENGTH, wth->fh) != NULL) {
 
-			reclen = strlen(buf);
+			reclen = (guint) strlen(buf);
 			if (reclen < TOSHIBA_HDR_MAGIC_SIZE) {
 				continue;
 			}
diff --git a/wiretap/visual.c b/wiretap/visual.c
index 7504ffa1cf..dee9cbf550 100644
--- a/wiretap/visual.c
+++ b/wiretap/visual.c
@@ -819,7 +819,7 @@ static gboolean visual_dump(wtap_dumper *wdh, const struct wtap_pkthdr *phdr,
 
     /* Update the table index and offset for the next frame. */
     visual->index_table_index++;
-    visual->next_offset += hdr_size + phdr->caplen;
+    visual->next_offset += (guint32) hdr_size + phdr->caplen;
 
     return TRUE;
 }
diff --git a/wiretap/vms.c b/wiretap/vms.c
index f834122897..905405d32e 100644
--- a/wiretap/vms.c
+++ b/wiretap/vms.c
@@ -222,7 +222,7 @@ static gboolean vms_check_file_type(wtap *wth, int *err)
     }
     if (file_gets(buf, VMS_LINE_LENGTH, wth->fh) != NULL) {
       
-      reclen = strlen(buf);
+      reclen = (guint) strlen(buf);
       if (reclen < strlen(VMS_HDR_MAGIC_STR1) ||
 	  reclen < strlen(VMS_HDR_MAGIC_STR2) || 
 	  reclen < strlen(VMS_HDR_MAGIC_STR3)) {
@@ -435,7 +435,7 @@ parse_vms_rec_hdr(wtap *wth, FILE_T fh, int *err, gchar **err_info)
     if (wth) {
         p = strstr(months, mon);
         if (p)
-            tm.tm_mon = (p - months) / 3;
+            tm.tm_mon = (int) (p - months) / 3;
         tm.tm_year -= 1900;
 
 	tm.tm_isdst = -1;