diff --git a/source/f90/Makefile b/source/f90/Makefile
index e722a8dc27571e9958514b6c7a240b5e5f51cf08..0fbf733e6b013adbcf11fea3dc3a15641e5216c5 100644
--- a/source/f90/Makefile
+++ b/source/f90/Makefile
@@ -22,7 +22,7 @@ PYTHON3 = python3
 all: boson eels eels-boson
 
 bosonmods = sicot_mod.mod sintr_mod.mod rcffi_mod.mod
-doboson.o: doboson.f90 $(bosonmods) o.o
+doboson.o: doboson.f90 $(bosonmods)
 
 sicot_mod.mod: sintr_mod.mod