--- a/GNUmakefile	2002-11-15 19:57:48.000000000 +0100
+++ a/GNUmakefile	2014-10-02 16:03:02.864803002 +0200
@@ -6,7 +6,7 @@
 LDCONFIG ?= /sbin/ldconfig
 
 # Some suggestions: (-mcpu= generates i386 compatible code)
-CFLAGS ?= -O2 -fomit-frame-pointer -pipe -mcpu=i686 -w
+CFLAGS ?= -O2 -pipe -Wall -Werror
 #CFLAGS = -O2 -fomit-frame-pointer -pipe -march=i586 -Wall -g
 #CFLAGS = -O6 -fomit-frame-pointer -pipe -march=i586 -Wall -ansi -pedantic
 #CFLAGS = -O6 -fomit-frame-pointer -pipe -march=i686 -Wall -ansi -pedantic
@@ -15,10 +15,9 @@
 #CFLAGS = -g -pg -a -pipe -march=i686 -Wall
 #LDFLAGS = -s
 
-prefix ?= /usr/local
+prefix ?= /usr
 libdir ?= $(prefix)/lib
 includedir ?= $(prefix)/include
-includedir ?= /usr/include
 
 PROGRAMS = avlsort setdiff
 LIBRARY = libavl.so.1.5
@@ -34,16 +33,17 @@
 	$(CC) $(LDFLAGS) $^ -o $@ $(LIBS)
 
 $(LIBRARY): avl.o
-	$(CC) -nostdlib -shared -Wl,-soname,libavl.so.1 $^ -o $@ -lc
+	$(CC) -shared -Wl,-soname,libavl.so.1 $^ -o $@ -lc
 
 clean:
 	$(RM) *.o $(PROGRAMS) libavl.*
 
 install: all
 	$(INSTALL) -d $(DESTDIR)$(libdir)
-	$(INSTALL) avl.h $(DESTDIR)$(includedir)
-	$(INSTALL) $(LIBRARIES) $(DESTDIR)$(libdir)
-	for i in $(LIBRARIES); do\
+	$(INSTALL) -d $(DESTDIR)$(includedir)
+	$(INSTALL) -m 644 avl.h $(DESTDIR)$(includedir)
+	$(INSTALL) -m 644 $(LIBRARY) $(DESTDIR)$(libdir)
+	for i in $(LIBRARY); do\
 		$(LN) -sf $$i $(DESTDIR)$(libdir)/$${i%.*};\
 		$(LN) -sf $${i%.*} $(DESTDIR)$(libdir)/$${i%.*.*};\
 	done
