diff --git a/src/cpu-features.h b/src/cpu-features.h
index cbec565..738fa69 100644
--- a/src/cpu-features.h
+++ b/src/cpu-features.h
@@ -378,8 +378,8 @@
   bool operator!=(const CPUFeaturesConstIterator& other) const {
     return !(*this == other);
   }
-  CPUFeatures::Feature operator++();
-  CPUFeatures::Feature operator++(int);
+  CPUFeaturesConstIterator& operator++();
+  CPUFeaturesConstIterator operator++(int);
 
   CPUFeatures::Feature operator*() const {
     VIXL_ASSERT(IsValid());