diff --git a/physics/module_mp_thompson.F90 b/physics/module_mp_thompson.F90
index ad3e0c48a..374bff393 100644
--- a/physics/module_mp_thompson.F90
+++ b/physics/module_mp_thompson.F90
@@ -50,7 +50,7 @@ MODULE module_mp_thompson
 
       USE module_mp_radar
 
-#if ! defined(SION) && defined(MPI)
+#if !defined(SION) && defined(MPI)
       use mpi
 #endif