diff --git a/alib2algo/makefile b/alib2algo/makefile
index d8b9e8ea69edc9872ddcc4c7f13fbd617fcc5800..b3c532f9b48cd1798e9581788d79a17d2873e89a 100644
--- a/alib2algo/makefile
+++ b/alib2algo/makefile
@@ -143,11 +143,11 @@ test: unit-test-debug unit-test-release
 
 
 
-lib-debug/$(LIBRARY): $(OBJECTS_DEBUG)
+lib-debug/$(LIBRARY): $(OBJECTS_DEBUG) obj-debug/
 	mkdir -p $(dir $@)
 	$(CXX) $(OBJECTS_DEBUG) -o $@ $(LDFLAGS_DEBUG)
 
-lib-release/$(LIBRARY): $(OBJECTS_RELEASE)
+lib-release/$(LIBRARY): $(OBJECTS_RELEASE) obj-release/
 	mkdir -p $(dir $@)
 	$(CXX) $(OBJECTS_RELEASE) -o $@ $(LDFLAGS_RELEASE)
 
@@ -172,11 +172,11 @@ build-release: lib-release/$(LIBRARY)
 
 
 
-test-bin-debug/$(TESTBIN): lib-debug/$(LIBRARY) $(TEST_OBJECTS_DEBUG)
+test-bin-debug/$(TESTBIN): lib-debug/$(LIBRARY) $(TEST_OBJECTS_DEBUG) test-obj-debug/
 	mkdir -p $(dir $@)
 	$(CXX) $(TEST_OBJECTS_DEBUG) -o $@ $(TEST_LDFLAGS_DEBUG)
 
-test-bin-release/$(TESTBIN): lib-release/$(LIBRARY) $(TEST_OBJECTS_RELEASE)
+test-bin-release/$(TESTBIN): lib-release/$(LIBRARY) $(TEST_OBJECTS_RELEASE) test-obj-release/
 	mkdir -p $(dir $@)
 	$(CXX) $(TEST_OBJECTS_RELEASE) -o $@ $(TEST_LDFLAGS_RELEASE)
 
diff --git a/alib2data/makefile b/alib2data/makefile
index 0c025d6a2b2f82fb1d61715f13ad0136ca82f249..9eb63cd1a4d3fa54c5f3835dee8e36512a3b52a2 100644
--- a/alib2data/makefile
+++ b/alib2data/makefile
@@ -141,11 +141,11 @@ test: unit-test-debug unit-test-release
 
 
 
-lib-debug/$(LIBRARY): $(OBJECTS_DEBUG)
+lib-debug/$(LIBRARY): $(OBJECTS_DEBUG) obj-debug/
 	mkdir -p $(dir $@)
 	$(CXX) $(OBJECTS_DEBUG) -o $@ $(LDFLAGS_DEBUG)
 
-lib-release/$(LIBRARY): $(OBJECTS_RELEASE)
+lib-release/$(LIBRARY): $(OBJECTS_RELEASE) obj-release/
 	mkdir -p $(dir $@)
 	$(CXX) $(OBJECTS_RELEASE) -o $@ $(LDFLAGS_RELEASE)
 
@@ -170,11 +170,11 @@ build-release: lib-release/$(LIBRARY)
 
 
 
-test-bin-debug/$(TESTBIN): lib-debug/$(LIBRARY) $(TEST_OBJECTS_DEBUG)
+test-bin-debug/$(TESTBIN): lib-debug/$(LIBRARY) $(TEST_OBJECTS_DEBUG) test-obj-debug/
 	mkdir -p $(dir $@)
 	$(CXX) $(TEST_OBJECTS_DEBUG) -o $@ $(TEST_LDFLAGS_DEBUG)
 
-test-bin-release/$(TESTBIN): lib-release/$(LIBRARY) $(TEST_OBJECTS_RELEASE)
+test-bin-release/$(TESTBIN): lib-release/$(LIBRARY) $(TEST_OBJECTS_RELEASE) test-obj-release/
 	mkdir -p $(dir $@)
 	$(CXX) $(TEST_OBJECTS_RELEASE) -o $@ $(TEST_LDFLAGS_RELEASE)