diff --git a/tests/bits/bitrev_test.c b/tests/bits/bitrev_test.c
index b96241c..ed3939a 100644
--- a/tests/bits/bitrev_test.c
+++ b/tests/bits/bitrev_test.c
@@ -208,6 +208,9 @@
 static void sh_chk(const uint8_t *in, uint8_t len, unsigned int nib, bool r)
 {
 	uint8_t x[len];
+	int bytes = nib/2 + (nib & 1);
+	OSMO_ASSERT(len >= bytes);
+	memset(x, 0xcc, len);
 	if (r)
 		osmo_nibble_shift_right(x, in, nib);
 	else
@@ -217,7 +220,7 @@
 	       osmo_hexdump_nospc(in, len), nib);
 	/* do NOT combine those printfs: osmo_hexdump* use static buffer which
 	   WILL screw things up in that case */
-	printf("\n     OUT: %s\n", osmo_hexdump_nospc(x, nib/2));
+	printf("\n     OUT: %s\n", osmo_hexdump_nospc(x, bytes));
 }
 
 int main(int argc, char **argv)
diff --git a/tests/bits/bitrev_test.ok b/tests/bits/bitrev_test.ok
index e6f52af..d2fb12c 100644
--- a/tests/bits/bitrev_test.ok
+++ b/tests/bits/bitrev_test.ok
@@ -63,13 +63,13 @@
 [6] L IN: b00bbabeface, nibble 0:
      OUT: 
 [8] R IN: f00dcafedeadbeef, nibble 1:
-     OUT: 
+     OUT: cc
 [8] L IN: f00dcafedeadbeef, nibble 1:
-     OUT: 
+     OUT: cc
 [6] R IN: b00bbabeface, nibble 1:
-     OUT: 
+     OUT: cc
 [6] L IN: b00bbabeface, nibble 1:
-     OUT: 
+     OUT: cc
 [8] R IN: f00dcafedeadbeef, nibble 2:
      OUT: 0f
 [8] L IN: f00dcafedeadbeef, nibble 2:
@@ -79,13 +79,13 @@
 [6] L IN: b00bbabeface, nibble 2:
      OUT: 00
 [8] R IN: f00dcafedeadbeef, nibble 3:
-     OUT: 0f
+     OUT: 0f00
 [8] L IN: f00dcafedeadbeef, nibble 3:
-     OUT: 00
+     OUT: 00d0
 [6] R IN: b00bbabeface, nibble 3:
-     OUT: 0b
+     OUT: 0b00
 [6] L IN: b00bbabeface, nibble 3:
-     OUT: 00
+     OUT: 00b0
 [8] R IN: f00dcafedeadbeef, nibble 4:
      OUT: 0f00
 [8] L IN: f00dcafedeadbeef, nibble 4:
@@ -95,13 +95,13 @@
 [6] L IN: b00bbabeface, nibble 4:
      OUT: 00bb
 [8] R IN: f00dcafedeadbeef, nibble 5:
-     OUT: 0f00
+     OUT: 0f00dc
 [8] L IN: f00dcafedeadbeef, nibble 5:
-     OUT: 00dc
+     OUT: 00dca0
 [6] R IN: b00bbabeface, nibble 5:
-     OUT: 0b00
+     OUT: 0b00bb
 [6] L IN: b00bbabeface, nibble 5:
-     OUT: 00bb
+     OUT: 00bba0
 [8] R IN: f00dcafedeadbeef, nibble 6:
      OUT: 0f00dc
 [8] L IN: f00dcafedeadbeef, nibble 6:
@@ -111,13 +111,13 @@
 [6] L IN: b00bbabeface, nibble 6:
      OUT: 00bbab
 [8] R IN: f00dcafedeadbeef, nibble 7:
-     OUT: 0f00dc
+     OUT: 0f00dcaf
 [8] L IN: f00dcafedeadbeef, nibble 7:
-     OUT: 00dcaf
+     OUT: 00dcafe0
 [6] R IN: b00bbabeface, nibble 7:
-     OUT: 0b00bb
+     OUT: 0b00bbab
 [6] L IN: b00bbabeface, nibble 7:
-     OUT: 00bbab
+     OUT: 00bbabe0
 [8] R IN: f00dcafedeadbeef, nibble 8:
      OUT: 0f00dcaf
 [8] L IN: f00dcafedeadbeef, nibble 8:
@@ -127,13 +127,13 @@
 [6] L IN: b00bbabeface, nibble 8:
      OUT: 00bbabef
 [8] R IN: f00dcafedeadbeef, nibble 9:
-     OUT: 0f00dcaf
+     OUT: 0f00dcafed
 [8] L IN: f00dcafedeadbeef, nibble 9:
-     OUT: 00dcafed
+     OUT: 00dcafede0
 [6] R IN: b00bbabeface, nibble 9:
-     OUT: 0b00bbab
+     OUT: 0b00bbabef
 [6] L IN: b00bbabeface, nibble 9:
-     OUT: 00bbabef
+     OUT: 00bbabefa0
 [8] R IN: f00dcafedeadbeef, nibble 10:
      OUT: 0f00dcafed
 [8] L IN: f00dcafedeadbeef, nibble 10:
@@ -143,13 +143,13 @@
 [6] L IN: b00bbabeface, nibble 10:
      OUT: 00bbabefac
 [8] R IN: f00dcafedeadbeef, nibble 11:
-     OUT: 0f00dcafed
+     OUT: 0f00dcafedea
 [8] L IN: f00dcafedeadbeef, nibble 11:
-     OUT: 00dcafedea
+     OUT: 00dcafedead0
 [6] R IN: b00bbabeface, nibble 11:
-     OUT: 0b00bbabef
+     OUT: 0b00bbabefac
 [6] L IN: b00bbabeface, nibble 11:
-     OUT: 00bbabefac
+     OUT: 00bbabeface0
 [8] R IN: f00dcafedeadbeef, nibble 12:
      OUT: 0f00dcafedea
 [8] L IN: f00dcafedeadbeef, nibble 12: