diff --git a/mlir/lib/Dialect/MemRef/IR/MemRefOps.cpp b/mlir/lib/Dialect/MemRef/IR/MemRefOps.cpp
--- a/mlir/lib/Dialect/MemRef/IR/MemRefOps.cpp
+++ b/mlir/lib/Dialect/MemRef/IR/MemRefOps.cpp
@@ -311,15 +311,23 @@
 
   LogicalResult matchAndRewrite(AllocaScopeOp op,
                                 PatternRewriter &rewriter) const override {
-    if (!op->getParentOp()->hasTrait<OpTrait::AutomaticAllocationScope>()) {
-      bool hasPotentialAlloca =
-          op->walk([&](Operation *alloc) {
-              if (alloc == op)
-                return WalkResult::advance();
-              if (isOpItselfPotentialAutomaticAllocation(alloc))
-                return WalkResult::interrupt();
+    bool hasPotentialAlloca =
+        op->walk([&](Operation *alloc) {
+            if (alloc == op)
               return WalkResult::advance();
-            }).wasInterrupted();
+            if (alloc
+                    ->getParentWithTrait<OpTrait::AutomaticAllocationScope>() !=
+                op)
+              return WalkResult::skip();
+            if (isOpItselfPotentialAutomaticAllocation(alloc)) {
+              return WalkResult::interrupt();
+            }
+            return WalkResult::advance();
+          }).wasInterrupted();
+
+    // If the parent isn't an allocation scope, and we contain an allocation
+    // we cannot inline the scope.
+    if (!op->getParentOp()->hasTrait<OpTrait::AutomaticAllocationScope>()) {
       if (hasPotentialAlloca)
         return failure();
     }
@@ -327,7 +335,7 @@
     // Only apply to if this is this last non-terminator
     // op in the block (lest lifetime be extended) of a one
     // block region
-    if (!lastNonTerminatorInRegion(op))
+    if (hasPotentialAlloca && !lastNonTerminatorInRegion(op))
       return failure();
 
     Block *block = &op.getRegion().front();
diff --git a/mlir/test/Dialect/MemRef/canonicalize.mlir b/mlir/test/Dialect/MemRef/canonicalize.mlir
--- a/mlir/test/Dialect/MemRef/canonicalize.mlir
+++ b/mlir/test/Dialect/MemRef/canonicalize.mlir
@@ -644,6 +644,32 @@
 // CHECK:     return
 // CHECK:   }
 
+func @scopeMerge5() {
+  "test.region"() ({
+    memref.alloca_scope {
+      affine.parallel (%arg) = (0) to (64) {
+        %a = memref.alloca(%arg) : memref<?xi64>
+        "test.use"(%a) : (memref<?xi64>) -> ()
+      }
+    }
+    "test.op"() : () -> ()
+    "test.terminator"() : () -> ()
+  }) : () -> ()
+  return
+}
+
+// CHECK:   func @scopeMerge5() {
+// CHECK:     "test.region"() ({
+// CHECK:       affine.parallel (%[[cnt:.+]]) = (0) to (64) {
+// CHECK:         %[[alloc:.+]] = memref.alloca(%[[cnt]]) : memref<?xi64>
+// CHECK:         "test.use"(%[[alloc]]) : (memref<?xi64>) -> ()
+// CHECK:       }
+// CHECK:       "test.op"() : () -> ()
+// CHECK:       "test.terminator"() : () -> ()
+// CHECK:     }) : () -> ()
+// CHECK:     return
+// CHECK:   }
+
 func @scopeInline(%arg : memref<index>) {
   %cnt = "test.count"() : () -> index
   "test.region"() ({