diff --git a/src/main.rs b/src/main.rs
index 859e9dd052..af3597aeb1 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -91,7 +91,7 @@ impl SchemeMut for RandScheme {
 }
 
 fn main(){
-    let has_rdrand = false;
+    let mut has_rdrand = false;
 
     #[cfg(target_arch = "x86_64")]
     {