diff --git a/tests/fdc-test.c b/tests/fdc-test.c
index c8e1e7bd18..203074cdad 100644
--- a/tests/fdc-test.c
+++ b/tests/fdc-test.c
@@ -65,7 +65,7 @@ enum {
     DSKCHG  = 0x80,
 };
 
-char test_image[] = "/tmp/qtest.XXXXXX";
+static char test_image[] = "/tmp/qtest.XXXXXX";
 
 #define assert_bit_set(data, mask) g_assert_cmphex((data) & (mask), ==, (mask))
 #define assert_bit_clear(data, mask) g_assert_cmphex((data) & (mask), ==, 0)
diff --git a/tests/test-aio.c b/tests/test-aio.c
index 4c40a4971f..f12b6e0ae8 100644
--- a/tests/test-aio.c
+++ b/tests/test-aio.c
@@ -15,7 +15,7 @@
 #include "qemu/timer.h"
 #include "qemu/sockets.h"
 
-AioContext *ctx;
+static AioContext *ctx;
 
 typedef struct {
     EventNotifier e;
diff --git a/tests/test-qemu-opts.c b/tests/test-qemu-opts.c
index 3653507f56..ca08ac523d 100644
--- a/tests/test-qemu-opts.c
+++ b/tests/test-qemu-opts.c
@@ -56,7 +56,7 @@ static QemuOptsList opts_list_02 = {
     },
 };
 
-QemuOptsList opts_list_03 = {
+static QemuOptsList opts_list_03 = {
     .name = "opts_list_03",
     .head = QTAILQ_HEAD_INITIALIZER(opts_list_03.head),
     .desc = {
diff --git a/tests/test-throttle.c b/tests/test-throttle.c
index 3de6ab80e0..000ae31af9 100644
--- a/tests/test-throttle.c
+++ b/tests/test-throttle.c
@@ -15,10 +15,10 @@
 #include "block/aio.h"
 #include "qemu/throttle.h"
 
-AioContext     *ctx;
-LeakyBucket    bkt;
-ThrottleConfig cfg;
-ThrottleState  ts;
+static AioContext     *ctx;
+static LeakyBucket    bkt;
+static ThrottleConfig cfg;
+static ThrottleState  ts;
 
 /* useful function */
 static bool double_cmp(double x, double y)
diff --git a/tests/test-visitor-serialization.c b/tests/test-visitor-serialization.c
index 74d6481992..7ad1886397 100644
--- a/tests/test-visitor-serialization.c
+++ b/tests/test-visitor-serialization.c
@@ -372,8 +372,8 @@ static void test_primitive_lists(gconstpointer opaque)
     TestArgs *args = (TestArgs *) opaque;
     const SerializeOps *ops = args->ops;
     PrimitiveType *pt = args->test_data;
-    PrimitiveList pl = { .value = { 0 } };
-    PrimitiveList pl_copy = { .value = { 0 } };
+    PrimitiveList pl = { .value = { NULL } };
+    PrimitiveList pl_copy = { .value = { NULL } };
     PrimitiveList *pl_copy_ptr = &pl_copy;
     Error *err = NULL;
     void *serialize_data;
@@ -771,7 +771,7 @@ static void test_nested_struct_list(gconstpointer opaque)
     g_free(args);
 }
 
-PrimitiveType pt_values[] = {
+static PrimitiveType pt_values[] = {
     /* string tests */
     {
         .description = "string_empty",
diff --git a/tests/test-vmstate.c b/tests/test-vmstate.c
index a462335c4b..d72c64c90b 100644
--- a/tests/test-vmstate.c
+++ b/tests/test-vmstate.c
@@ -29,8 +29,8 @@
 #include "migration/vmstate.h"
 #include "block/coroutine.h"
 
-char temp_file[] = "/tmp/vmst.test.XXXXXX";
-int temp_fd;
+static char temp_file[] = "/tmp/vmst.test.XXXXXX";
+static int temp_fd;
 
 /* Fake yield_until_fd_readable() implementation so we don't have to pull the
  * coroutine code as dependency.