diff --git a/src/Makefile b/src/Makefile
index fea10f3..286e6d1 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -15,7 +15,5 @@ include $(PVDATASRC)/monitor/Makefile
 LIBRARY = pvData
 pvData_LIBS += Com
 
-USR_CXXFLAGS_RTEMS = -D__rtems__
-
 include $(TOP)/configure/RULES