diff --git a/all b/all
index 12acaf3..8f78ee4 100755
--- a/all
+++ b/all
@@ -1,4 +1,6 @@
-cd testes
+make -s -j
+cd testes/libs; make -s
+cd ..     # back to directory 'testes'
 ulimit -S -s 2000
 if { ../lua all.lua; } then 
   echo -e "\n\n    final OK!!!!\n\n"
diff --git a/makefile b/makefile
index 02a0814..3bd319b 100644
--- a/makefile
+++ b/makefile
@@ -90,6 +90,7 @@
 ALL_A= $(CORE_T)
 
 all:	$(ALL_T)
+	touch all
 
 o:	$(ALL_O)
 
diff --git a/testes/libs/makefile b/testes/libs/makefile
index 9925fb0..acff484 100644
--- a/testes/libs/makefile
+++ b/testes/libs/makefile
@@ -9,18 +9,19 @@
 
 # libraries used by the tests
 all: lib1.so lib11.so lib2.so lib21.so lib2-v2.so
+	touch all
 
-lib1.so: lib1.c
+lib1.so: lib1.c $(LUA_DIR)/luaconf.h $(LUA_DIR)/ltests.h
 	$(CC) $(CFLAGS) -o lib1.so lib1.c
 
-lib11.so: lib11.c
+lib11.so: lib11.c $(LUA_DIR)/luaconf.h $(LUA_DIR)/ltests.h
 	$(CC) $(CFLAGS) -o lib11.so lib11.c
 
-lib2.so: lib2.c
+lib2.so: lib2.c $(LUA_DIR)/luaconf.h $(LUA_DIR)/ltests.h
 	$(CC) $(CFLAGS) -o lib2.so lib2.c
 
-lib21.so: lib21.c
+lib21.so: lib21.c $(LUA_DIR)/luaconf.h $(LUA_DIR)/ltests.h
 	$(CC) $(CFLAGS) -o lib21.so lib21.c
 
 lib2-v2.so: lib2.so
-	mv lib2.so ./lib2-v2.so
+	cp lib2.so ./lib2-v2.so