diff --git a/lib/Analysis/BadCallChecker.cpp b/lib/Analysis/BadCallChecker.cpp
new file mode 100644
index 0000000..33bb515
--- /dev/null
+++ b/lib/Analysis/BadCallChecker.cpp
@@ -0,0 +1,44 @@
+//===--- BadCallChecker.h - Bad call checker --------------------*- C++ -*--==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This defines BadCallChecker, a builtin check in GRExprEngine that performs
+// checks for bad callee at call sites.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Analysis/PathSensitive/Checkers/BadCallChecker.h"
+#include "clang/Analysis/PathSensitive/BugReporter.h"
+
+using namespace clang;
+
+void *BadCallChecker::getTag() {
+  static int x = 0;
+  return &x;
+}
+
+void BadCallChecker::PreVisitCallExpr(CheckerContext &C, const CallExpr *CE) {
+  const Expr *Callee = CE->getCallee()->IgnoreParens();
+  SVal L = C.getState()->getSVal(Callee);
+
+  if (L.isUndef() || isa<loc::ConcreteInt>(L)) {
+    if (ExplodedNode *N = C.GenerateNode(CE, true)) {
+      if (!BT)
+        BT = new BuiltinBug(0, "Invalid function call",
+                "Called function pointer is a null or undefined pointer value");
+
+      EnhancedBugReport *R =
+        new EnhancedBugReport(*BT, BT->getDescription().c_str(), N);
+        
+      R->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue,
+                           bugreporter::GetCalleeExpr(N));
+
+      C.EmitReport(R);
+    }
+  }
+}