diff --git a/Utility/Inc/utility_function.hpp b/Utility/Inc/utility_function.hpp
index e01078c..0d62c67 100644
--- a/Utility/Inc/utility_function.hpp
+++ b/Utility/Inc/utility_function.hpp
@@ -8,6 +8,8 @@
 #ifndef SKULLC_UTILITY_FUNCTION_HPP_
 #define SKULLC_UTILITY_FUNCTION_HPP_
 
+#include <utility_assert.hpp>
+
 namespace Utility
 {
 
@@ -49,7 +51,7 @@ public:
   explicit Function(signature callable)
       : callable_(callable)
   {
-    assert(callable_);
+    SKULLC_ASSERT_DEBUG(callable_);
   }
 
   ~Function() override
@@ -81,7 +83,7 @@ public:
   explicit FunctionOwned(source& src, signature callable)
       : src_(&src), callable_(callable)
   {
-    assert(callable_);
+    SKULLC_ASSERT_DEBUG(callable_);
   }
 
   ~FunctionOwned() override