diff --git a/lib/CodeGen/CGClass.cpp b/lib/CodeGen/CGClass.cpp
index 2789bb2..2cb5549 100644
--- a/lib/CodeGen/CGClass.cpp
+++ b/lib/CodeGen/CGClass.cpp
@@ -1305,6 +1305,7 @@
   if (ClassDecl->hasTrivialDestructor()) return;
 
   const CXXDestructorDecl *D = ClassDecl->getDestructor();
+  assert(D && D->isUsed() && "destructor not marked as used!");
   PushDestructorCleanup(D, Addr);
 }
 
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 73fe000..c4ec8dc 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -1124,8 +1124,18 @@
 
   // Build a copy expression.
   Expr *copyExpr = 0;
-  if (!byRef && S.getLangOptions().CPlusPlus &&
-      !type->isDependentType() && type->isStructureOrClassType()) {
+  const RecordType *rtype;
+  if (!byRef && S.getLangOptions().CPlusPlus && !type->isDependentType() &&
+      (rtype = type->getAs<RecordType>())) {
+
+    // The capture logic needs the destructor, so make sure we mark it.
+    // Usually this is unnecessary because most local variables have
+    // their destructors marked at declaration time, but parameters are
+    // an exception because it's technically only the call site that
+    // actually requires the destructor.
+    if (isa<ParmVarDecl>(var))
+      S.FinalizeVarWithDestructor(var, rtype);
+
     // According to the blocks spec, the capture of a variable from
     // the stack requires a const copy constructor.  This is not true
     // of the copy/move done to move a __block variable to the heap.
diff --git a/test/CodeGenCXX/blocks.cpp b/test/CodeGenCXX/blocks.cpp
index d66debe..a4d5b86 100644
--- a/test/CodeGenCXX/blocks.cpp
+++ b/test/CodeGenCXX/blocks.cpp
@@ -87,3 +87,20 @@
   // CHECK: define internal void @__Block_byref_object_dispose
   // CHECK: call void @_ZN5test21BD1Ev(
 }
+
+// rdar://problem/9334739
+// Make sure we mark destructors for parameters captured in blocks.
+namespace test3 {
+  struct A {
+    A(const A&);
+    ~A();
+  };
+
+  struct B : A {
+  };
+
+  void test(B b) {
+    extern void consume(void(^)());
+    consume(^{ (void) b; });
+  }
+}