diff --git a/lib/Analysis/GRExprEngine.cpp b/lib/Analysis/GRExprEngine.cpp
index fb52067..343ac69 100644
--- a/lib/Analysis/GRExprEngine.cpp
+++ b/lib/Analysis/GRExprEngine.cpp
@@ -1820,6 +1820,14 @@
       
       Expr* SE = VLA->getSizeExpr();
       SVal Size = GetSVal(St, SE);
+      
+      if (Size.isUndef()) {
+        if (NodeTy* N = Builder->generateNode(DS, St, Pred)) {
+          N->markAsSink();          
+          ExplicitBadSizedVLA.insert(N);
+        }
+        continue;
+      }
 
       bool isFeasibleZero = false;
       const GRState* ZeroSt =  Assume(St, Size, false, isFeasibleZero);
@@ -1830,8 +1838,8 @@
       if (isFeasibleZero) {
         if (NodeTy* N = Builder->generateNode(DS, ZeroSt, Pred)) {
           N->markAsSink();          
-          if (isFeasibleNotZero) ImplicitZeroSizedVLA.insert(N);
-          else ExplicitZeroSizedVLA.insert(N);
+          if (isFeasibleNotZero) ImplicitBadSizedVLA.insert(N);
+          else ExplicitBadSizedVLA.insert(N);
         }
       }
       
diff --git a/lib/Analysis/GRExprEngineInternalChecks.cpp b/lib/Analysis/GRExprEngineInternalChecks.cpp
index 8b484ab..d32318c 100644
--- a/lib/Analysis/GRExprEngineInternalChecks.cpp
+++ b/lib/Analysis/GRExprEngineInternalChecks.cpp
@@ -40,6 +40,7 @@
 
 namespace {
 class VISIBILITY_HIDDEN BuiltinBug : public BugTypeCacheLocation {
+protected:
   const char* name;
   const char* desc;
 public:
@@ -332,26 +333,45 @@
   }
 };
   
-class VISIBILITY_HIDDEN ZeroSizeVLA : public BuiltinBug {
+class VISIBILITY_HIDDEN BadSizeVLA : public BuiltinBug {
 
 public:
-  ZeroSizeVLA() : BuiltinBug("Zero-sized VLA",  
+  BadSizeVLA() : BuiltinBug("Zero-sized VLA",  
                              "VLAs with zero-size are undefined.") {}
   
   virtual void EmitBuiltinWarnings(BugReporter& BR, GRExprEngine& Eng) {
     for (GRExprEngine::ErrorNodes::iterator
-          I = Eng.ExplicitZeroSizedVLA.begin(),
-          E = Eng.ExplicitZeroSizedVLA.end(); I!=E; ++I) {
-      
-      // Generate a report for this bug.
-      PostStmt PS = cast<PostStmt>((*I)->getLocation());      
+          I = Eng.ExplicitBadSizedVLA.begin(),
+          E = Eng.ExplicitBadSizedVLA.end(); I!=E; ++I) {
+
+      // Determine whether this was a 'zero-sized' VLA or a VLA with an
+      // undefined size.
+      GRExprEngine::NodeTy* N = *I;
+      PostStmt PS = cast<PostStmt>(N->getLocation());      
       DeclStmt *DS = cast<DeclStmt>(PS.getStmt());
       VarDecl* VD = cast<VarDecl>(*DS->decl_begin());
       QualType T = Eng.getContext().getCanonicalType(VD->getType());
       VariableArrayType* VT = cast<VariableArrayType>(T);
+      Expr* SizeExpr = VT->getSizeExpr();
       
-      RangedBugReport report(*this, *I);
-      report.addRange(VT->getSizeExpr()->getSourceRange());
+      std::string buf;
+      llvm::raw_string_ostream os(buf);
+      os << "The expression used to specify the number of elements in the VLA '"
+          << VD->getNameAsString() << "' evaluates to ";
+      
+      SVal X = Eng.getStateManager().GetSVal(N->getState(), SizeExpr);
+      if (X.isUndef()) {
+        name = "Undefined size for VLA";
+        os << "an undefined or garbage value.";
+      }
+      else {
+        name = "Zero-sized VLA";
+        os << " to 0.  VLAs with no elements have undefined behavior.";
+      }
+
+      desc = os.str().c_str();
+      RangedBugReport report(*this, N);
+      report.addRange(SizeExpr->getSourceRange());
       
       // Emit the warning.
       BR.EmitWarning(report);
@@ -430,6 +450,6 @@
   Register(new BadMsgExprArg());
   Register(new BadReceiver());
   Register(new OutOfBoundMemoryAccess());
-  Register(new ZeroSizeVLA());
+  Register(new BadSizeVLA());
   AddCheck(new CheckAttrNonNull(), Stmt::CallExprClass); 
 }