diff --git a/example/storage_tank.cpp b/example/storage_tank.cpp
index e1e457ce..74de7482 100644
--- a/example/storage_tank.cpp
+++ b/example/storage_tank.cpp
@@ -31,8 +31,7 @@ import mp_units;
 #else
 #include <mp-units/format.h>
 #include <mp-units/math.h>
-#include <mp-units/systems/isq/mechanics.h>
-#include <mp-units/systems/isq/space_and_time.h>
+#include <mp-units/systems/isq/isq.h>
 #include <mp-units/systems/si/si.h>
 #endif