Index: uspace/lib/cpp/include/internal/builtins.hpp
===================================================================
--- uspace/lib/cpp/include/internal/builtins.hpp	(revision e7a4f417314c09ce9664824457d2ae5b51ac4483)
+++ uspace/lib/cpp/include/internal/builtins.hpp	(revision 6b81ca53303d14db05f1f3e33bccd7173e7e501e)
@@ -65,7 +65,7 @@
 
     template<class T>
-    constexpr double ceil(T val)
+    constexpr size_t ceil(T val)
     {
-        return __builtin_ceil(static_cast<double>(val));
+        return static_cast<size_t>(__builtin_ceil(static_cast<double>(val)));
     }
 }