diff --git a/src/Makefile.global.in b/src/Makefile.global.in
index 1a0faf9023..d4fed90405 100644
--- a/src/Makefile.global.in
+++ b/src/Makefile.global.in
@@ -893,7 +893,7 @@ coverage: $(local_gcda_files:.gcda=.c.gcov)
 .PHONY: coverage-html
 coverage-html: coverage-html-stamp
 
-GENHTML_FLAGS = --show-details --legend
+GENHTML_FLAGS = --legend
 GENHTML_TITLE = PostgreSQL $(VERSION)
 
 coverage-html-stamp: lcov_base.info lcov_test.info