diff --git a/unit_tests/rules.mk b/unit_tests/rules.mk
index c9724b657a..dc28ae4244 100644
--- a/unit_tests/rules.mk
+++ b/unit_tests/rules.mk
@@ -165,6 +165,7 @@ else
 endif
 
 $(BUILDDIR)/$(PROJECT): $(OBJS)
+	rm -rf $(BUILDDIR)/obj/*gcda
 ifeq ($(USE_VERBOSE_COMPILE),yes)
 	@echo
 	$(LD) $(OBJS) $(LDFLAGS) $(LIBS) -o $@