diff --git a/lib/bitmap.c b/lib/bitmap.c
index 06f7e4f..e5c4ebe 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -131,7 +131,9 @@
 		lower = src[off + k];
 		if (left && off + k == lim - 1)
 			lower &= mask;
-		dst[k] = upper << (BITS_PER_LONG - rem) | lower >> rem;
+		dst[k] = lower >> rem;
+		if (rem)
+			dst[k] |= upper << (BITS_PER_LONG - rem);
 		if (left && k == lim - 1)
 			dst[k] &= mask;
 	}
@@ -172,7 +174,9 @@
 		upper = src[k];
 		if (left && k == lim - 1)
 			upper &= (1UL << left) - 1;
-		dst[k + off] = lower  >> (BITS_PER_LONG - rem) | upper << rem;
+		dst[k + off] = upper << rem;
+		if (rem)
+			dst[k + off] |= lower >> (BITS_PER_LONG - rem);
 		if (left && k + off == lim - 1)
 			dst[k + off] &= (1UL << left) - 1;
 	}