diff --git a/dumb/src/it/readokt.c b/dumb/src/it/readokt.c
index 9ae059575..1f2fa9443 100644
--- a/dumb/src/it/readokt.c
+++ b/dumb/src/it/readokt.c
@@ -497,7 +497,7 @@ static DUMB_IT_SIGDATA *it_okt_load_sigdata(DUMBFILE *f, int restrict)
 			j++;
 		}
 	}
-	for (; i < sigdata->n_samples; i++) {
+	for (; i < (unsigned)sigdata->n_samples; i++) {
 		sigdata->sample[i].flags = 0;
 	}
 
diff --git a/dumb/src/it/readstm.c b/dumb/src/it/readstm.c
index be1b15720..a4b00f79b 100644
--- a/dumb/src/it/readstm.c
+++ b/dumb/src/it/readstm.c
@@ -354,7 +354,7 @@ static DUMB_IT_SIGDATA *it_stm_load_sigdata(DUMBFILE *f, int * version)
 
 	for ( n = 0, q = o / 16; n < sigdata->n_samples; ++n ) {
 		if ( sample_offset[ n ] ) {
-			sample_offset[ n ] -= q;
+			sample_offset[ n ] = (unsigned short)(sample_offset[ n ] - q);
 		}
 	}
 
diff --git a/dumb/src/it/readxm.c b/dumb/src/it/readxm.c
index 4e3dbee0b..1930ba938 100644
--- a/dumb/src/it/readxm.c
+++ b/dumb/src/it/readxm.c
@@ -400,14 +400,14 @@ static int limit_xm_resize(void *f, long n)
 	return 0;
 }
 
-static int limit_xm_skip_end(void *f, long n)
+static int limit_xm_skip_end(void *f, int32 n)
 {
 	DUMBFILE *df = f;
 	LIMITED_XM *lx = df->file;
 	return dumbfile_skip( lx->remaining, n );
 }
 
-static int limit_xm_skip(void *f, long n)
+static int limit_xm_skip(void *f, int32 n)
 {
 	LIMITED_XM *lx = f;
 	lx->ptr += n;
@@ -427,7 +427,7 @@ static int limit_xm_getc(void *f)
 
 
 
-static long limit_xm_getnc(char *ptr, long n, void *f)
+static long limit_xm_getnc(char *ptr, int32 n, void *f)
 {
 	LIMITED_XM *lx = f;
 	int left;