diff --git a/test/filter_test_data.cpp b/test/filter_test_data.cpp
index 28da2863..1b6b64e4 100644
--- a/test/filter_test_data.cpp
+++ b/test/filter_test_data.cpp
@@ -111,7 +111,7 @@ R"(
 
 }
 
-std::vector<filter_test_data> const& get_filter_tests() { return filter_tests; }
+std::span<filter_test_data const> get_filter_tests() { return filter_tests; }
 
 std::ostream& operator<<(std::ostream& os, filter_test_data const& data) {
   os << data.test_name();
diff --git a/test/filter_test_data.h b/test/filter_test_data.h
index a9a9a944..eda16d79 100644
--- a/test/filter_test_data.h
+++ b/test/filter_test_data.h
@@ -24,6 +24,7 @@
 #pragma once
 
 #include <iosfwd>
+#include <span>
 #include <string>
 #include <string_view>
 #include <unordered_set>
@@ -55,7 +56,7 @@ class filter_test_data {
   std::unordered_set<std::string> expected_files_;
 };
 
-std::vector<filter_test_data> const& get_filter_tests();
+std::span<filter_test_data const> get_filter_tests();
 
 std::ostream& operator<<(std::ostream& os, filter_test_data const& data);