--- Makefile.linux~	2005-05-04 16:10:07.000000000 +0800
+++ Makefile.linux	2012-12-08 09:02:40.526617125 +0800
@@ -28,7 +28,7 @@
 all: easychem po/
 
 easychem: postscript/ graph/ $(OBJECTS)
-	$(CC) -o easychem $(OBJECTS) $(GTK_LIBS) $(C_FLAGS)
+	$(CC) -o easychem $(OBJECTS) $(GTK_LIBS) $(C_FLAGS) -lm
 	strip easychem
 
 clean: FORCE