diff --git a/include/llvm/Instruction.h b/include/llvm/Instruction.h
index 031730a9759..25be14fbd21 100644
--- a/include/llvm/Instruction.h
+++ b/include/llvm/Instruction.h
@@ -39,7 +39,7 @@ public:
   //
   inline const BasicBlock *getParent() const { return Parent; }
   inline       BasicBlock *getParent()       { return Parent; }
-  bool hasSideEffects() const { return false; }  // Memory & Call insts = true
+  virtual bool hasSideEffects() const { return false; }  // Memory & Call insts
 
   // ---------------------------------------------------------------------------
   // Subclass classification... getInstType() returns a member of 
diff --git a/include/llvm/iMemory.h b/include/llvm/iMemory.h
index feed3a2f883..fe045d72667 100644
--- a/include/llvm/iMemory.h
+++ b/include/llvm/iMemory.h
@@ -95,6 +95,8 @@ public:
   virtual Instruction *clone() const { return new FreeInst(Operands[0]); }
 
   virtual const char *getOpcodeName() const { return "free"; }
+
+  virtual bool hasSideEffects() const { return true; }
 };
 
 
@@ -155,6 +157,8 @@ public:
 	    const string &Name = "");
   virtual Instruction *clone() const { return new StoreInst(*this); }
   virtual const char *getOpcodeName() const { return "store"; }  
+
+  virtual bool hasSideEffects() const { return true; }
 };