diff --git a/t/perf/p5310-pack-bitmaps.sh b/t/perf/p5310-pack-bitmaps.sh
index 6e8abcd5b21..adc753b6177 100755
--- a/t/perf/p5310-pack-bitmaps.sh
+++ b/t/perf/p5310-pack-bitmaps.sh
@@ -17,39 +17,50 @@ test_expect_success 'setup bitmap config' '
 	git config pack.writeReverseIndex true
 '
 
-# we need to create the tag up front such that it is covered by the repack and
-# thus by generated bitmaps.
-test_expect_success 'create tags' '
-	git tag --message="tag pointing to HEAD" perf-tag HEAD
-'
+test_bitmap () {
+	local enabled="$1"
 
-test_perf 'repack to disk' '
-	git repack -ad
-'
+	# we need to create the tag up front such that it is covered by the repack and
+	# thus by generated bitmaps.
+	test_expect_success 'create tags' '
+		git tag --message="tag pointing to HEAD" perf-tag HEAD
+	'
 
-test_full_bitmap
+	test_expect_success "use lookup table: $enabled" '
+		git config pack.writeBitmapLookupTable '"$enabled"'
+	'
 
-test_expect_success 'create partial bitmap state' '
-	# pick a commit to represent the repo tip in the past
-	cutoff=$(git rev-list HEAD~100 -1) &&
-	orig_tip=$(git rev-parse HEAD) &&
+	test_perf "repack to disk (lookup=$enabled)" '
+		git repack -ad
+	'
 
-	# now kill off all of the refs and pretend we had
-	# just the one tip
-	rm -rf .git/logs .git/refs/* .git/packed-refs &&
-	git update-ref HEAD $cutoff &&
+	test_full_bitmap
 
-	# and then repack, which will leave us with a nice
-	# big bitmap pack of the "old" history, and all of
-	# the new history will be loose, as if it had been pushed
-	# up incrementally and exploded via unpack-objects
-	git repack -Ad &&
+	test_expect_success "create partial bitmap state (lookup=$enabled)" '
+		# pick a commit to represent the repo tip in the past
+		cutoff=$(git rev-list HEAD~100 -1) &&
+		orig_tip=$(git rev-parse HEAD) &&
 
-	# and now restore our original tip, as if the pushes
-	# had happened
-	git update-ref HEAD $orig_tip
-'
+		# now kill off all of the refs and pretend we had
+		# just the one tip
+		rm -rf .git/logs .git/refs/* .git/packed-refs &&
+		git update-ref HEAD $cutoff &&
+
+		# and then repack, which will leave us with a nice
+		# big bitmap pack of the "old" history, and all of
+		# the new history will be loose, as if it had been pushed
+		# up incrementally and exploded via unpack-objects
+		git repack -Ad &&
+
+		# and now restore our original tip, as if the pushes
+		# had happened
+		git update-ref HEAD $orig_tip
+	'
+
+	test_partial_bitmap
+}
 
-test_partial_bitmap
+test_bitmap false
+test_bitmap true
 
 test_done
diff --git a/t/perf/p5326-multi-pack-bitmaps.sh b/t/perf/p5326-multi-pack-bitmaps.sh
index f2fa228f16a..1f4c7103529 100755
--- a/t/perf/p5326-multi-pack-bitmaps.sh
+++ b/t/perf/p5326-multi-pack-bitmaps.sh
@@ -6,47 +6,58 @@ test_description='Tests performance using midx bitmaps'
 
 test_perf_large_repo
 
-# we need to create the tag up front such that it is covered by the repack and
-# thus by generated bitmaps.
-test_expect_success 'create tags' '
-	git tag --message="tag pointing to HEAD" perf-tag HEAD
-'
-
-test_expect_success 'start with bitmapped pack' '
-	git repack -adb
-'
-
-test_perf 'setup multi-pack index' '
-	git multi-pack-index write --bitmap
-'
-
-test_expect_success 'drop pack bitmap' '
-	rm -f .git/objects/pack/pack-*.bitmap
-'
-
-test_full_bitmap
-
-test_expect_success 'create partial bitmap state' '
-	# pick a commit to represent the repo tip in the past
-	cutoff=$(git rev-list HEAD~100 -1) &&
-	orig_tip=$(git rev-parse HEAD) &&
-
-	# now pretend we have just one tip
-	rm -rf .git/logs .git/refs/* .git/packed-refs &&
-	git update-ref HEAD $cutoff &&
-
-	# and then repack, which will leave us with a nice
-	# big bitmap pack of the "old" history, and all of
-	# the new history will be loose, as if it had been pushed
-	# up incrementally and exploded via unpack-objects
-	git repack -Ad &&
-	git multi-pack-index write --bitmap &&
-
-	# and now restore our original tip, as if the pushes
-	# had happened
-	git update-ref HEAD $orig_tip
-'
-
-test_partial_bitmap
+test_bitmap () {
+	local enabled="$1"
+
+	# we need to create the tag up front such that it is covered by the repack and
+	# thus by generated bitmaps.
+	test_expect_success 'create tags' '
+		git tag --message="tag pointing to HEAD" perf-tag HEAD
+	'
+
+	test_expect_success "use lookup table: $enabled" '
+		git config pack.writeBitmapLookupTable '"$enabled"'
+	'
+
+	test_expect_success "start with bitmapped pack (lookup=$enabled)" '
+		git repack -adb
+	'
+
+	test_perf "setup multi-pack index (lookup=$enabled)" '
+		git multi-pack-index write --bitmap
+	'
+
+	test_expect_success "drop pack bitmap (lookup=$enabled)" '
+		rm -f .git/objects/pack/pack-*.bitmap
+	'
+
+	test_full_bitmap
+
+	test_expect_success "create partial bitmap state (lookup=$enabled)" '
+		# pick a commit to represent the repo tip in the past
+		cutoff=$(git rev-list HEAD~100 -1) &&
+		orig_tip=$(git rev-parse HEAD) &&
+
+		# now pretend we have just one tip
+		rm -rf .git/logs .git/refs/* .git/packed-refs &&
+		git update-ref HEAD $cutoff &&
+
+		# and then repack, which will leave us with a nice
+		# big bitmap pack of the "old" history, and all of
+		# the new history will be loose, as if it had been pushed
+		# up incrementally and exploded via unpack-objects
+		git repack -Ad &&
+		git multi-pack-index write --bitmap &&
+
+		# and now restore our original tip, as if the pushes
+		# had happened
+		git update-ref HEAD $orig_tip
+	'
+
+	test_partial_bitmap
+}
+
+test_bitmap false
+test_bitmap true
 
 test_done
