diff --git a/compiler/GHC/StgToCmm/Prim.hs b/compiler/GHC/StgToCmm/Prim.hs
index 495f8b181b79da3b754d50161383ab468c5d02ec..b957b11b3e890384b8165ed99bc8283cfe8400c3 100644
--- a/compiler/GHC/StgToCmm/Prim.hs
+++ b/compiler/GHC/StgToCmm/Prim.hs
@@ -2302,8 +2302,8 @@ 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