diff --git a/INSTALL b/INSTALL
index a1fdb2d..794d553 100644
--- a/INSTALL
+++ b/INSTALL
@@ -14,6 +14,7 @@ php5
 ** Compilation of extra libraries **
 
 lib is not included by default and must be downloaded http://indefero.soutade.fr/p/kisscount/downloads/
+It must be decompressed beside "src" directory.
 
 cd lib/wxsqlite3-1.9.9
 ./configure
diff --git a/Makefile b/Makefile
index cd69603..d753805 100644
--- a/Makefile
+++ b/Makefile
@@ -20,7 +20,7 @@ HEADERS+=$(wildcard src/controller/*.h)
 HEADERS+=src/main.h src/sha1.h
 OBJS=$(SOURCES:.cpp=.o)
 
-all: kc
+all: check kc
 
 clean:
 	rm -f *~ src/*~ src/*.o src/model/*.o src/model/*~ src/view/*.o src/view/grid/*.o src/view/grid/*~ src/view/*~ src/controller/*.o src/controller/*~ kc
@@ -28,6 +28,9 @@ clean:
 %.o : src/model/%.cpp src/view/%.cpp src/view/grid/%.cpp src/controller/%.cpp src/%.cpp
 	$(CXX) $(CXXFLAGS) $< -c
 
+check:
+	if ! test -d lib ; then echo lib directory not found, please see INSTALL ; return 1 ; fi
+
 kc: $(OBJS)
 	$(CXX) $(CXXFLAGS) $^ -o $@ $(LDFLAGS)