diff --git a/compiler/GHC/StgToCmm/Prim.hs b/compiler/GHC/StgToCmm/Prim.hs
index f3130cf6d268a27f472de29a2486158ffbb209df..eb3672445c6f2f3c22c7328f096de99cc5fe3e4c 100644
--- a/compiler/GHC/StgToCmm/Prim.hs
+++ b/compiler/GHC/StgToCmm/Prim.hs
@@ -2180,8 +2180,8 @@ alignmentFromTypes :: CmmType  -- ^ element type
                    -> CmmType  -- ^ index type
                    -> AlignmentSpec
 alignmentFromTypes ty idx_ty
-  | typeWidth ty < typeWidth idx_ty = NaturallyAligned
-  | otherwise                       = Unaligned
+  | typeWidth ty <= typeWidth idx_ty = NaturallyAligned
+  | otherwise                        = Unaligned
 
 doIndexOffAddrOp :: Maybe MachOp
                  -> CmmType