diff --git a/src/libCom/Makefile b/src/libCom/Makefile
index a7a7b9957..c34f4971f 100644
--- a/src/libCom/Makefile
+++ b/src/libCom/Makefile
@@ -14,6 +14,9 @@ LIBCOM = $(TOP)/src/libCom
 
 USR_CXXFLAGS_hpux += -D_REENTRANT
 
+# Command-line input support
+epicsReadline_CFLAGS += -DEPICS_COMMANDLINE_LIBRARY=EPICS_COMMANDLINE_LIBRARY_$(COMMANDLINE_LIBRARY)
+
 #epicsVersion is created by this Makefile
 INC += epicsVersion.h