diff --git a/mlir/lib/Dialect/Affine/IR/AffineOps.cpp b/mlir/lib/Dialect/Affine/IR/AffineOps.cpp
--- a/mlir/lib/Dialect/Affine/IR/AffineOps.cpp
+++ b/mlir/lib/Dialect/Affine/IR/AffineOps.cpp
@@ -629,9 +629,9 @@
   MLIRContext *ctx = map->getContext();
   AffineExpr toReplace = isDimReplacement ? getAffineDimExpr(pos, ctx)
                                           : getAffineSymbolExpr(pos, ctx);
-  *map = map->replace(toReplace, composeExpr, dims.size(), syms.size());
   dims.append(composeDims.begin(), composeDims.end());
   syms.append(composeSyms.begin(), composeSyms.end());
+  *map = map->replace(toReplace, composeExpr, dims.size(), syms.size());
 
   return success();
 }