diff --git a/lib/util/bitmap.c b/lib/util/bitmap.c
index 63963356f98..12cdfe4d16a 100644
--- a/lib/util/bitmap.c
+++ b/lib/util/bitmap.c
@@ -74,7 +74,7 @@ bool bitmap_set(struct bitmap *bm, unsigned i)
 		      i, bm->n));
 		return false;
 	}
-	bm->b[i/32] |= (1<<(i%32));
+	bm->b[i/32] |= (1U<<(i%32));
 	return true;
 }
 
@@ -88,7 +88,7 @@ bool bitmap_clear(struct bitmap *bm, unsigned i)
 		      i, bm->n));
 		return false;
 	}
-	bm->b[i/32] &= ~(1<<(i%32));
+	bm->b[i/32] &= ~(1U<<(i%32));
 	return true;
 }
 
@@ -98,7 +98,7 @@ query a bit in a bitmap
 bool bitmap_query(struct bitmap *bm, unsigned i)
 {
 	if (i >= bm->n) return false;
-	if (bm->b[i/32] & (1<<(i%32))) {
+	if (bm->b[i/32] & (1U<<(i%32))) {
 		return true;
 	}
 	return false;