diff --git a/include/remill/BC/Compat/CallSite.h b/include/remill/BC/Compat/CallSite.h
index d8a7b2324..a5ffa47fa 100644
--- a/include/remill/BC/Compat/CallSite.h
+++ b/include/remill/BC/Compat/CallSite.h
@@ -48,6 +48,7 @@ namespace remill::compat::llvm {
     using parent::getCalledValue;
     using parent::getCalledFunction;
     using parent::setCalledFunction;
+    using parent::getInstruction;
   };
 
 } // namespace remill::compat::llvm
@@ -55,6 +56,8 @@ namespace remill::compat::llvm {
 #else
 
 #include <llvm/IR/AbstractCallSite.h>
+#include <llvm/Analysis/InlineCost.h>
+#include <llvm/Transforms/Utils/Cloning.h>
 namespace remill::compat::llvm {
 
   struct CallSite {
@@ -83,7 +86,7 @@ namespace remill::compat::llvm {
       return cb->getCalledOperand();
     }
 
-    ::llvm::Function *getCalledFunction() {
+    ::llvm::Function *getCalledFunction() const {
       if ( !*this) {
         return nullptr;
       }
@@ -97,6 +100,10 @@ namespace remill::compat::llvm {
     operator bool() const {
       return cb;
     }
+
+    ::llvm::CallBase *getInstruction() {
+      return cb;
+    }
   };
 
 } // namespace remill::compat::llvm
diff --git a/include/remill/BC/Compat/Cloning.h b/include/remill/BC/Compat/Cloning.h
new file mode 100644
index 000000000..4f83b903e
--- /dev/null
+++ b/include/remill/BC/Compat/Cloning.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2021 Trail of Bits, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#pragma once
+
+#include "remill/BC/Version.h"
+
+/* This compatibility relates to the changes made in CallSite.h.
+ */
+
+#if LLVM_VERSION_NUMBER >= LLVM_VERSION(11, 0)
+
+#include <llvm/IR/AbstractCallSite.h>
+#include <llvm/Analysis/InlineCost.h>
+#include <llvm/Transforms/Utils/Cloning.h>
+
+namespace llvm {
+
+  inline static InlineResult InlineFunction(CallBase *CB, InlineFunctionInfo &IFI,
+                                            AAResults *CalleeAAR = nullptr,
+                                            bool InsertLifetime = true,
+                                            Function *ForwardVarArgsTo = nullptr) {
+    return InlineFunction(*CB, IFI, CalleeAAR, InsertLifetime, ForwardVarArgsTo);
+  }
+
+}  // namespace llvm
+
+#endif