diff --git a/Makefile.in b/Makefile.in
index bbbc877..7e8c144 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -185,6 +185,7 @@ INSTALL_DATA = $(INSTALL) -p -m 644
 
 ifeq ("@TESTING@", "yes")
 TEST_INCLUDES=\
+	-I$(TOP_DIR) \
 	-Igoogletest/googlemock/include \
 	-Igoogletest/googletest/include
 else
diff --git a/unit-tests/Makefile.in b/unit-tests/Makefile.in
index 971b485..d4af3b2 100644
--- a/unit-tests/Makefile.in
+++ b/unit-tests/Makefile.in
@@ -78,9 +78,9 @@ TEST_OBJECTS=$(subst .cc,.gmo,$(TEST_SOURCE))
 
 %.gmo: %.cc
 	@echo "    [CXX] $<"
-	$(V) $(CXX) -c $(CPPFLAGS) $(GMOCK_INCLUDES) $(CXXFLAGS) $(GMOCK_FLAGS) -o $@ $<
+	$(V) $(CXX) -c $(TEST_INCLUDES) $(CPPFLAGS) $(GMOCK_INCLUDES) $(CXXFLAGS) $(GMOCK_FLAGS) -o $@ $<
 	@echo "    [DEP] $<"
-	$(V) $(CXX) -MM -MT $(subst .cc,.o,$<) $(CPPFLAGS) $(GMOCK_INCLUDES) $(CXXFLAGS) $(GMOCK_FLAGS) $< > $*.$$$$; \
+	$(V) $(CXX) -MM -MT $(subst .cc,.o,$<) $(TEST_INCLUDES) $(CPPFLAGS) $(GMOCK_INCLUDES) $(CXXFLAGS) $(GMOCK_FLAGS) $< > $*.$$$$; \
 	sed 's,\([^ :]*\)\.o[ :]*,\1.o \1.gmo $* : Makefile ,g' < $*.$$$$ > $*.d; \
 	$(RM) $*.$$$$