diff --git a/src/drv_imap.c b/src/drv_imap.c
index ee2d1a8..90d1b95 100644
--- a/src/drv_imap.c
+++ b/src/drv_imap.c
@@ -2377,7 +2377,7 @@ imap_open_store_ssl_bail( imap_store_t *ctx )
 static void
 imap_open_store_bail( imap_store_t *ctx, int failed )
 {
-	((imap_store_conf_t *)ctx->gen.conf)->server->failed = failed;
+	((imap_store_conf_t *)ctx->gen.conf)->server->failed = (char)failed;
 	ctx->callbacks.imap_open( DRV_STORE_BAD, ctx->callback_aux );
 }
 
diff --git a/src/drv_maildir.c b/src/drv_maildir.c
index bb98d3f..d8179de 100644
--- a/src/drv_maildir.c
+++ b/src/drv_maildir.c
@@ -1017,7 +1017,7 @@ maildir_scan( maildir_store_t *ctx, msg_t_array_alloc_t *msglist )
 					entry->base = nfstrdup( e->d_name );
 					entry->msgid = 0;
 					entry->uid = uid;
-					entry->recent = i;
+					entry->recent = (uchar)i;
 					entry->size = 0;
 					entry->tuid[0] = 0;
 				}
diff --git a/src/sync.c b/src/sync.c
index 0d62bb8..c34c7c2 100644
--- a/src/sync.c
+++ b/src/sync.c
@@ -957,11 +957,11 @@ load_state( sync_vars_t *svars )
 						break;
 					case '*':
 						debug( "flags now %u\n", t3 );
-						srec->flags = t3;
+						srec->flags = (uchar)t3;
 						break;
 					case '~':
 						debug( "status now %#x\n", t3 );
-						srec->status = t3;
+						srec->status = (uchar)t3;
 						break;
 					default:
 						error( "Error: unrecognized journal entry at %s:%d\n", svars->jname, line );
@@ -1895,7 +1895,7 @@ msgs_copied( sync_vars_t *svars, int t )
 				}
 				for (uint i = 0; i < TUIDL; i++) {
 					uchar c = arc4_getbyte() & 0x3f;
-					srec->tuid[i] = c < 26 ? c + 'A' : c < 52 ? c + 'a' - 26 : c < 62 ? c + '0' - 52 : c == 62 ? '+' : '/';
+					srec->tuid[i] = (char)(c < 26 ? c + 'A' : c < 52 ? c + 'a' - 26 : c < 62 ? c + '0' - 52 : c == 62 ? '+' : '/');
 				}
 				jFprintf( svars, "# %u %u %." stringify(TUIDL) "s\n", srec->uid[M], srec->uid[S], srec->tuid );
 				debug( "%sing message %u, TUID %." stringify(TUIDL) "s\n", str_hl[t], tmsg->uid, srec->tuid );
diff --git a/src/util.c b/src/util.c
index fc8c8df..09ac55f 100644
--- a/src/util.c
+++ b/src/util.c
@@ -592,7 +592,7 @@ arc4_init( void )
 	close( fd );
 
 	for (i = 0; i < 256; i++)
-		rs.s[i] = i;
+		rs.s[i] = (uchar)i;
 	for (i = j = 0; i < 256; i++) {
 		si = rs.s[i];
 		j += si + dat[i & 127];