diff --git a/base_class/Makefile b/base_class/Makefile
index 7a5d802..d2deabc 100644
--- a/base_class/Makefile
+++ b/base_class/Makefile
@@ -72,7 +72,3 @@ FILES = $(SRCS) EST_Pathname_win32.cc $(T) $(H)\
 ALL = .buildlib $(BUILD_DIRS)
 
 include $(TOP)/config/common_make_rules
-
-# Always compile with -O3 as its an important function
-rateconv.o:
-	$(CXX_COMMAND) -O3 rateconv.cc -o rateconv.o