diff --git a/src/distance_neon.cc b/src/distance_neon.cc
index 8e8783e..1abcda6 100644
--- a/src/distance_neon.cc
+++ b/src/distance_neon.cc
@@ -45,7 +45,7 @@ int distance_neon(const std::vector<GeneBlock> &a,
       r_b = vceqzq_u8(r_b);
       // only keep LSB for each uint8 to get either 0 or 1
       r_a = vandq_u8(r_a, lsb);
-      r_b = vandq_u8(r_b, lsb);
+      r_b = vandq_u8(r_a, lsb);
       // add these values to distance counts
       r_s = vaddq_u8(r_s, r_a);
       r_s = vaddq_u8(r_s, r_b);