diff --git a/t/perf/perf-lib.sh b/t/perf/perf-lib.sh
index b15c74d6f1..2ac007888e 100644
--- a/t/perf/perf-lib.sh
+++ b/t/perf/perf-lib.sh
@@ -20,7 +20,7 @@
 # These variables must be set before the inclusion of test-lib.sh below,
 # because it will change our working directory.
 TEST_DIRECTORY=$(pwd)/..
-TEST_OUTPUT_DIRECTORY=$(pwd)
+perf_dir=$(pwd)
 
 TEST_NO_CREATE_REPO=t
 TEST_NO_MALLOC_CHECK=t
@@ -58,6 +58,7 @@ then
 fi
 
 . "$GIT_BUILD_DIR"/GIT-BUILD-OPTIONS
+: ${TEST_OUTPUT_DIRECTORY:=$perf_dir}
 . "$GIT_SOURCE_DIR"/t/test-lib.sh
 
 # Then restore GIT_PERF_* settings.
diff --git a/t/perf/run b/t/perf/run
index 073bcb2aff..13913db4a3 100755
--- a/t/perf/run
+++ b/t/perf/run
@@ -204,8 +204,18 @@ run_subsection () {
 get_var_from_env_or_config "GIT_PERF_CODESPEED_OUTPUT" "perf" "codespeedOutput" "--bool"
 get_var_from_env_or_config "GIT_PERF_SEND_TO_CODESPEED" "perf" "sendToCodespeed"
 
+# Preserve GIT_PERF settings from the environment when loading
+# GIT-BUILD-OPTIONS; see the similar hack in perf-lib.sh.
+git_perf_settings="$(env |
+        sed -n "/^GIT_PERF_/{
+                # escape all single-quotes in the value
+                s/'/'\\\\''/g
+                # turn this into an eval-able assignment
+                s/^\\([^=]*=\\)\\(.*\\)/\\1'\\2'/p
+        }")"
 cd "$(dirname $0)"
 . ../../GIT-BUILD-OPTIONS
+eval "$git_perf_settings"
 
 if test -n "$TEST_OUTPUT_DIRECTORY"
 then