diff --git a/source/compare_neon64.cc b/source/compare_neon64.cc
index cc078f84c..6d1e5e1bc 100644
--- a/source/compare_neon64.cc
+++ b/source/compare_neon64.cc
@@ -32,7 +32,7 @@ uint32 SumSquareError_NEON(const uint8* src_a, const uint8* src_b, int count) {
     "ld1        {v0.16b}, [%0], #16            \n"
     MEMACCESS(1)
     "ld1        {v1.16b}, [%1], #16            \n"
-    "subs       %2, %2, #16                    \n"
+    "subs       %w2, %w2, #16                  \n"
     "usubl      v2.8h, v0.8b, v1.8b            \n"
     "usubl2     v3.8h, v0.16b, v1.16b          \n"
     "smlal      v16.4s, v2.4h, v2.4h           \n"