diff -urN ./ytree-1.92.orig/Makefile ./ytree-1.92/Makefile
--- ./ytree-1.92.orig/Makefile	2009-01-31 20:57:46.000000000 +0100
+++ ./ytree-1.92/Makefile	2009-01-31 20:58:11.000000000 +0100
@@ -32,7 +32,7 @@
 COLOR       = -DCOLOR_SUPPORT 
 CLOCK	    = -DCLOCK_SUPPORT # Experimental!
 READLINE    = -DREADLINE_SUPPORT
-CFLAGS      = -D_GNU_SOURCE $(ADD_CFLAGS) $(COLOR) $(CLOCK) $(READLINE)
+CFLAGS      += -D_GNU_SOURCE $(ADD_CFLAGS) $(COLOR) $(CLOCK) $(READLINE)
 LDFLAGS     = -lncurses -lreadline
 
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