diff --git a/lib/Analysis/AliasAnalysisSummary.cpp b/lib/Analysis/AliasAnalysisSummary.cpp
index 2b48794..2f3396a 100644
--- a/lib/Analysis/AliasAnalysisSummary.cpp
+++ b/lib/Analysis/AliasAnalysisSummary.cpp
@@ -73,28 +73,28 @@
 }
 
 Optional<InstantiatedValue> instantiateInterfaceValue(InterfaceValue IValue,
-                                                      CallSite CS) {
+                                                      CallBase &Call) {
   auto Index = IValue.Index;
-  auto Value = (Index == 0) ? CS.getInstruction() : CS.getArgument(Index - 1);
-  if (Value->getType()->isPointerTy())
-    return InstantiatedValue{Value, IValue.DerefLevel};
+  auto *V = (Index == 0) ? &Call : Call.getArgOperand(Index - 1);
+  if (V->getType()->isPointerTy())
+    return InstantiatedValue{V, IValue.DerefLevel};
   return None;
 }
 
 Optional<InstantiatedRelation>
-instantiateExternalRelation(ExternalRelation ERelation, CallSite CS) {
-  auto From = instantiateInterfaceValue(ERelation.From, CS);
+instantiateExternalRelation(ExternalRelation ERelation, CallBase &Call) {
+  auto From = instantiateInterfaceValue(ERelation.From, Call);
   if (!From)
     return None;
-  auto To = instantiateInterfaceValue(ERelation.To, CS);
+  auto To = instantiateInterfaceValue(ERelation.To, Call);
   if (!To)
     return None;
   return InstantiatedRelation{*From, *To, ERelation.Offset};
 }
 
 Optional<InstantiatedAttr> instantiateExternalAttribute(ExternalAttribute EAttr,
-                                                        CallSite CS) {
-  auto Value = instantiateInterfaceValue(EAttr.IValue, CS);
+                                                        CallBase &Call) {
+  auto Value = instantiateInterfaceValue(EAttr.IValue, Call);
   if (!Value)
     return None;
   return InstantiatedAttr{*Value, EAttr.Attr};
diff --git a/lib/Analysis/AliasAnalysisSummary.h b/lib/Analysis/AliasAnalysisSummary.h
index 8ac3bf9..fe75b03 100644
--- a/lib/Analysis/AliasAnalysisSummary.h
+++ b/lib/Analysis/AliasAnalysisSummary.h
@@ -37,7 +37,7 @@
 #include "llvm/ADT/DenseMapInfo.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/SmallVector.h"
-#include "llvm/IR/CallSite.h"
+#include "llvm/IR/InstrTypes.h"
 #include <bitset>
 
 namespace llvm {
@@ -195,12 +195,13 @@
   SmallVector<ExternalAttribute, 8> RetParamAttributes;
 };
 
-/// This is the result of instantiating InterfaceValue at a particular callsite
+/// This is the result of instantiating InterfaceValue at a particular call
 struct InstantiatedValue {
   Value *Val;
   unsigned DerefLevel;
 };
-Optional<InstantiatedValue> instantiateInterfaceValue(InterfaceValue, CallSite);
+Optional<InstantiatedValue> instantiateInterfaceValue(InterfaceValue IValue,
+                                                      CallBase &Call);
 
 inline bool operator==(InstantiatedValue LHS, InstantiatedValue RHS) {
   return LHS.Val == RHS.Val && LHS.DerefLevel == RHS.DerefLevel;
@@ -228,8 +229,8 @@
   InstantiatedValue From, To;
   int64_t Offset;
 };
-Optional<InstantiatedRelation> instantiateExternalRelation(ExternalRelation,
-                                                           CallSite);
+Optional<InstantiatedRelation>
+instantiateExternalRelation(ExternalRelation ERelation, CallBase &Call);
 
 /// This is the result of instantiating ExternalAttribute at a particular
 /// callsite
@@ -237,8 +238,8 @@
   InstantiatedValue IValue;
   AliasAttrs Attr;
 };
-Optional<InstantiatedAttr> instantiateExternalAttribute(ExternalAttribute,
-                                                        CallSite);
+Optional<InstantiatedAttr> instantiateExternalAttribute(ExternalAttribute EAttr,
+                                                        CallBase &Call);
 }
 
 template <> struct DenseMapInfo<cflaa::InstantiatedValue> {
diff --git a/lib/Analysis/CFLGraph.h b/lib/Analysis/CFLGraph.h
index 8fa6e88..5783c5b 100644
--- a/lib/Analysis/CFLGraph.h
+++ b/lib/Analysis/CFLGraph.h
@@ -24,7 +24,6 @@
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/IR/Argument.h"
 #include "llvm/IR/BasicBlock.h"
-#include "llvm/IR/CallSite.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/Function.h"
@@ -190,9 +189,9 @@
 
     // Returns possible functions called by CS into the given SmallVectorImpl.
     // Returns true if targets found, false otherwise.
-    static bool getPossibleTargets(CallSite CS,
+    static bool getPossibleTargets(CallBase &Call,
                                    SmallVectorImpl<Function *> &Output) {
-      if (auto *Fn = CS.getCalledFunction()) {
+      if (auto *Fn = Call.getCalledFunction()) {
         Output.push_back(Fn);
         return true;
       }
@@ -369,11 +368,11 @@
       return !Fn->hasExactDefinition();
     }
 
-    bool tryInterproceduralAnalysis(CallSite CS,
+    bool tryInterproceduralAnalysis(CallBase &Call,
                                     const SmallVectorImpl<Function *> &Fns) {
       assert(Fns.size() > 0);
 
-      if (CS.arg_size() > MaxSupportedArgsInSummary)
+      if (Call.arg_size() > MaxSupportedArgsInSummary)
         return false;
 
       // Exit early if we'll fail anyway
@@ -381,7 +380,7 @@
         if (isFunctionExternal(Fn) || Fn->isVarArg())
           return false;
         // Fail if the caller does not provide enough arguments
-        assert(Fn->arg_size() <= CS.arg_size());
+        assert(Fn->arg_size() <= Call.arg_size());
         if (!AA.getAliasSummary(*Fn))
           return false;
       }
@@ -392,7 +391,7 @@
 
         auto &RetParamRelations = Summary->RetParamRelations;
         for (auto &Relation : RetParamRelations) {
-          auto IRelation = instantiateExternalRelation(Relation, CS);
+          auto IRelation = instantiateExternalRelation(Relation, Call);
           if (IRelation.hasValue()) {
             Graph.addNode(IRelation->From);
             Graph.addNode(IRelation->To);
@@ -402,7 +401,7 @@
 
         auto &RetParamAttributes = Summary->RetParamAttributes;
         for (auto &Attribute : RetParamAttributes) {
-          auto IAttr = instantiateExternalAttribute(Attribute, CS);
+          auto IAttr = instantiateExternalAttribute(Attribute, Call);
           if (IAttr.hasValue())
             Graph.addNode(IAttr->IValue, IAttr->Attr);
         }
@@ -411,37 +410,35 @@
       return true;
     }
 
-    void visitCallSite(CallSite CS) {
-      auto Inst = CS.getInstruction();
-
+    void visitCallBase(CallBase &Call) {
       // Make sure all arguments and return value are added to the graph first
-      for (Value *V : CS.args())
+      for (Value *V : Call.args())
         if (V->getType()->isPointerTy())
           addNode(V);
-      if (Inst->getType()->isPointerTy())
-        addNode(Inst);
+      if (Call.getType()->isPointerTy())
+        addNode(&Call);
 
       // Check if Inst is a call to a library function that
       // allocates/deallocates on the heap. Those kinds of functions do not
       // introduce any aliases.
       // TODO: address other common library functions such as realloc(),
       // strdup(), etc.
-      if (isMallocOrCallocLikeFn(Inst, &TLI) || isFreeCall(Inst, &TLI))
+      if (isMallocOrCallocLikeFn(&Call, &TLI) || isFreeCall(&Call, &TLI))
         return;
 
       // TODO: Add support for noalias args/all the other fun function
       // attributes that we can tack on.
       SmallVector<Function *, 4> Targets;
-      if (getPossibleTargets(CS, Targets))
-        if (tryInterproceduralAnalysis(CS, Targets))
+      if (getPossibleTargets(Call, Targets))
+        if (tryInterproceduralAnalysis(Call, Targets))
           return;
 
       // Because the function is opaque, we need to note that anything
       // could have happened to the arguments (unless the function is marked
       // readonly or readnone), and that the result could alias just about
       // anything, too (unless the result is marked noalias).
-      if (!CS.onlyReadsMemory())
-        for (Value *V : CS.args()) {
+      if (!Call.onlyReadsMemory())
+        for (Value *V : Call.args()) {
           if (V->getType()->isPointerTy()) {
             // The argument itself escapes.
             Graph.addAttr(InstantiatedValue{V, 0}, getAttrEscaped());
@@ -452,12 +449,12 @@
           }
         }
 
-      if (Inst->getType()->isPointerTy()) {
-        auto *Fn = CS.getCalledFunction();
+      if (Call.getType()->isPointerTy()) {
+        auto *Fn = Call.getCalledFunction();
         if (Fn == nullptr || !Fn->returnDoesNotAlias())
           // No need to call addNode() since we've added Inst at the
           // beginning of this function and we know it is not a global.
-          Graph.addAttr(InstantiatedValue{Inst, 0}, getAttrUnknown());
+          Graph.addAttr(InstantiatedValue{&Call, 0}, getAttrUnknown());
       }
     }