diff --git a/trainer.h b/trainer.h
index 08aaa1675cfe703c22bd27795b489afaffeda463..26a285543c9cd2f6b7e8a5a5c0ae55356733777c 100644
--- a/trainer.h
+++ b/trainer.h
@@ -152,7 +152,7 @@ class Trainer {
 #endif
 };
 #ifdef TADAH_BUILD_MPI
-class MPI_Trainer public Trainer {
+class MPI_Trainer: public Trainer {
   MPI_Trainer(Config &c):
     Trainer(c)
   {}