diff --git a/mlir/include/mlir/Dialect/Transform/IR/TransformOps.td b/mlir/include/mlir/Dialect/Transform/IR/TransformOps.td
--- a/mlir/include/mlir/Dialect/Transform/IR/TransformOps.td
+++ b/mlir/include/mlir/Dialect/Transform/IR/TransformOps.td
@@ -24,7 +24,7 @@
         ["getSuccessorEntryOperands", "getSuccessorRegions",
          "getRegionInvocationBounds"]>,
      DeclareOpInterfaceMethods<TransformOpInterface>,
-     FunctionalStyleTransformOpTrait, MemoryEffectsOpInterface,
+     DeclareOpInterfaceMethods<MemoryEffectsOpInterface>,
      IsolatedFromAbove, PossibleTopLevelTransformOpTrait,
      SingleBlockImplicitTerminator<"::mlir::transform::YieldOp">]> {
   let summary = "Attempts sequences of transforms until one succeeds";
diff --git a/mlir/lib/Dialect/Transform/IR/TransformOps.cpp b/mlir/lib/Dialect/Transform/IR/TransformOps.cpp
--- a/mlir/lib/Dialect/Transform/IR/TransformOps.cpp
+++ b/mlir/lib/Dialect/Transform/IR/TransformOps.cpp
@@ -240,6 +240,17 @@
   return emitSilenceableError() << "all alternatives failed";
 }
 
+void transform::AlternativesOp::getEffects(
+    SmallVectorImpl<MemoryEffects::EffectInstance> &effects) {
+  consumesHandle(getOperands(), effects);
+  producesHandle(getResults(), effects);
+  for (Region *region : getRegions()) {
+    if (!region->empty())
+      producesHandle(region->front().getArguments(), effects);
+  }
+  modifiesPayload(effects);
+}
+
 LogicalResult transform::AlternativesOp::verify() {
   for (Region &alternative : getAlternatives()) {
     Block &block = alternative.front();
diff --git a/mlir/lib/Dialect/Transform/Transforms/CheckUses.cpp b/mlir/lib/Dialect/Transform/Transforms/CheckUses.cpp
--- a/mlir/lib/Dialect/Transform/Transforms/CheckUses.cpp
+++ b/mlir/lib/Dialect/Transform/Transforms/CheckUses.cpp
@@ -140,7 +140,13 @@
       return live();
 
 #ifndef NDEBUG
-    // Check that the definition point actually allcoates the value.
+    // Check that the definition point actually allocates the value. If the
+    // definition is a block argument, it may be just forwarding the operand of
+    // the parent op without doing a new allocation, allow that. We currently
+    // don't have the capability to analyze region-based control flow here.
+    //
+    // TODO: when this ported to the dataflow analysis infra, we should have
+    // proper support for region-based control flow.
     Operation *valueSource =
         operand.get().isa<OpResult>()
             ? operand.get().getDefiningOp()
@@ -149,7 +155,8 @@
     SmallVector<MemoryEffects::EffectInstance> instances;
     iface.getEffectsOnResource(transform::TransformMappingResource::get(),
                                instances);
-    assert(hasEffect<MemoryEffects::Allocate>(instances, operand.get()) &&
+    assert((operand.get().isa<BlockArgument>() ||
+            hasEffect<MemoryEffects::Allocate>(instances, operand.get())) &&
            "expected the op defining the value to have an allocation effect "
            "on it");
 #endif
diff --git a/mlir/test/Dialect/Transform/check-use-after-free.mlir b/mlir/test/Dialect/Transform/check-use-after-free.mlir
--- a/mlir/test/Dialect/Transform/check-use-after-free.mlir
+++ b/mlir/test/Dialect/Transform/check-use-after-free.mlir
@@ -167,3 +167,13 @@
   return
 }
 
+// -----
+
+// This should not crash.
+
+transform.sequence failures(propagate) {
+^bb0(%arg0: !pdl.operation):
+  alternatives %arg0 : !pdl.operation {
+  ^bb0(%arg1: !pdl.operation):
+  }
+}