diff --git a/lib/com_err/Makefile.am b/lib/com_err/Makefile.am
index 8c027c74d..14e8e66fc 100644
--- a/lib/com_err/Makefile.am
+++ b/lib/com_err/Makefile.am
@@ -2,7 +2,7 @@
 
 include $(top_srcdir)/Makefile.am.common
 
-YFLAGS = -d
+YFLAGS = -d -o parse.c
 LFLAGS = @FLEXNOUNPUTARGS@
 
 lib_LTLIBRARIES = libcom_err.la