diff --git a/opt.cpp b/opt.cpp
index e4b4b61f..a78c3f21 100644
--- a/opt.cpp
+++ b/opt.cpp
@@ -1156,8 +1156,12 @@ lIs248Splat(llvm::Value *v, int *splat) {
     if (cvec == NULL)
         return false;
 
+    llvm::Constant *splatConst = cvec->getSplatValue();
+    if (splatConst == NULL)
+        return false;
+
     llvm::ConstantInt *ci = 
-        llvm::dyn_cast<llvm::ConstantInt>(cvec->getSplatValue());
+        llvm::dyn_cast<llvm::ConstantInt>(splatConst);
     if (ci == NULL)
         return false;