diff --git a/include/llvm-c/Core.h b/include/llvm-c/Core.h
index 70fc6999530..2eccc11aa46 100644
--- a/include/llvm-c/Core.h
+++ b/include/llvm-c/Core.h
@@ -1166,6 +1166,7 @@ namespace llvm {
     for (LLVMValueRef *I = Vals, *E = Vals + Length; I != E; ++I)
       cast<T>(*I);
     #endif
+    (void)Length;
     return reinterpret_cast<T**>(Vals);
   }