diff --git a/third_party/subzero/src/IceTargetLoweringX86BaseImpl.h b/third_party/subzero/src/IceTargetLoweringX86BaseImpl.h
index 96e3e6b..a932e19 100644
--- a/third_party/subzero/src/IceTargetLoweringX86BaseImpl.h
+++ b/third_party/subzero/src/IceTargetLoweringX86BaseImpl.h
@@ -6487,8 +6487,6 @@
       }
       break;
       CASE_SRCS_IN(0, 0, 0, 1) : {
-        assert(false && "Following code is untested but likely correct; test "
-                        "and remove assert.");
         auto *Unified = lowerShuffleVector_UnifyFromDifferentSrcs(Src0, Index2,
                                                                   Src1, Index3);
         T = lowerShuffleVector_TwoFromSameSrc(Src0, Index0, Index1, Unified,