diff --git a/perf/benchmark-font.cc b/perf/benchmark-font.cc
index 89651673d..86282d6de 100644
--- a/perf/benchmark-font.cc
+++ b/perf/benchmark-font.cc
@@ -30,8 +30,8 @@ struct test_input_t
   {false, SUBSET_FONT_BASE_PATH "NotoSerifMyanmar-Regular.otf"},
 };
 
-test_input_t *tests = default_tests;
-unsigned num_tests = sizeof (default_tests) / sizeof (default_tests[0]);
+static test_input_t *tests = default_tests;
+static unsigned num_tests = sizeof (default_tests) / sizeof (default_tests[0]);
 
 enum backend_t { HARFBUZZ, FREETYPE };
 
diff --git a/perf/benchmark-shape.cc b/perf/benchmark-shape.cc
index 085da5d42..2f6e8682b 100644
--- a/perf/benchmark-shape.cc
+++ b/perf/benchmark-shape.cc
@@ -55,8 +55,8 @@ struct test_input_t
    true},
 };
 
-test_input_t *tests = default_tests;
-unsigned num_tests = sizeof (default_tests) / sizeof (default_tests[0]);
+static test_input_t *tests = default_tests;
+static unsigned num_tests = sizeof (default_tests) / sizeof (default_tests[0]);
 
 enum backend_t { HARFBUZZ, FREETYPE };
 
diff --git a/test/threads/hb-shape-threads.cc b/test/threads/hb-shape-threads.cc
index bc74b7289..f8821a7d8 100644
--- a/test/threads/hb-shape-threads.cc
+++ b/test/threads/hb-shape-threads.cc
@@ -56,14 +56,14 @@ struct test_input_t
    true},
 };
 
-test_input_t *tests = default_tests;
-unsigned num_tests = sizeof (default_tests) / sizeof (default_tests[0]);
+static test_input_t *tests = default_tests;
+static unsigned num_tests = sizeof (default_tests) / sizeof (default_tests[0]);
 
 enum backend_t { HARFBUZZ, FREETYPE };
 
 // https://en.cppreference.com/w/cpp/thread/condition_variable/wait
-std::condition_variable cv;
-std::mutex cv_m;
+static std::condition_variable cv;
+static std::mutex cv_m;
 static bool ready = false;
 
 static unsigned num_repetitions = 1;