diff --git a/src/Makefile.global.in b/src/Makefile.global.in
index a4209df7c95..27ec54a417f 100644
--- a/src/Makefile.global.in
+++ b/src/Makefile.global.in
@@ -898,7 +898,7 @@ GENHTML_TITLE = PostgreSQL $(VERSION)
 
 coverage-html-stamp: lcov_base.info lcov_test.info
 	rm -rf coverage
-	$(GENHTML) $(GENHTML_FLAGS) -o coverage --title='$(GENHTML_TITLE)' --num-spaces=4 $^
+	$(GENHTML) $(GENHTML_FLAGS) -o coverage --title='$(GENHTML_TITLE)' --num-spaces=4 $(if $(filter no,$(vpath_build)),--prefix='$(abs_top_srcdir)') $^
 	touch $@
 
 LCOV += --gcov-tool $(GCOV)