diff --git a/test/slice.cpp b/test/slice.cpp
index 997efd2f..a78a5e3d 100644
--- a/test/slice.cpp
+++ b/test/slice.cpp
@@ -76,7 +76,7 @@ bool check_numeric_array_rich_slice()
 // Verify functions accepting a slice argument can be called
 bool accept_slice( slice) { return true; }
 
-int check_slice_get_indicies(slice index);
+int check_slice_get_indicies(const slice index);
 int check_slice_get_indicies(const slice index)
 {
     // A vector of integers from [-5, 5].