diff --git a/src/hb-open-type.hh b/src/hb-open-type.hh
index 01c29f74c..0a6b16fd3 100644
--- a/src/hb-open-type.hh
+++ b/src/hb-open-type.hh
@@ -462,14 +462,12 @@ struct UnsizedArrayOf
 
   HB_DELETE_CREATE_COPY_ASSIGN (UnsizedArrayOf);
 
-  const Type& operator [] (int i_) const
+  const Type& operator [] (unsigned int i) const
   {
-    unsigned int i = (unsigned int) i_;
     return arrayZ[i];
   }
-  Type& operator [] (int i_)
+  Type& operator [] (unsigned int i)
   {
-    unsigned int i = (unsigned int) i_;
     return arrayZ[i];
   }