diff --git a/src/mx/system/topology.h b/src/mx/system/topology.h
index fcdbb6d..e5ed240 100644
--- a/src/mx/system/topology.h
+++ b/src/mx/system/topology.h
@@ -2,6 +2,7 @@
 
 #include <algorithm>
 #include <cstdint>
+#include "environment.h"
 
 namespace mx::system {
 /**
@@ -35,7 +36,7 @@ public:
     /**
      * @return Number of available cores.
      */
-    static std::uint16_t count_cores() { return std::uint16_t(Environment::env.cpu().affinity_space().total);
+    static std::uint16_t count_cores() { return std::uint16_t(Environment::env.cpu().affinity_space().total());
      }
 };
 } // namespace mx::system
\ No newline at end of file