diff --git a/Source/driver/castro_limits.H b/Source/driver/castro_limits.H
index 0111b43432..31ddeb93a9 100644
--- a/Source/driver/castro_limits.H
+++ b/Source/driver/castro_limits.H
@@ -1,6 +1,6 @@
 #ifndef CASTRO_LIMITS_H
 #define CASTRO_LIMITS_H
 
-#define MAX_LEV 15
+constexpr int MAX_LEV{15};
 
 #endif