diff --git a/gio/tests/async-splice-output-stream.c b/gio/tests/async-splice-output-stream.c
index e69c4db5d..dff65077d 100644
--- a/gio/tests/async-splice-output-stream.c
+++ b/gio/tests/async-splice-output-stream.c
@@ -193,6 +193,9 @@ main (int   argc,
 {
   g_test_init (&argc, &argv, NULL);
 
+  /* gvfs leaks like a sieve (mostly on purpose) */
+  g_setenv ("GIO_MODULE_DIR", "/non-existant", TRUE);
+
   g_test_add_func ("/async-splice/copy-chunks", test_copy_chunks);
   g_test_add_func ("/async-splice/copy-chunks-threaded-input",
                    test_copy_chunks_threaded_input);
diff --git a/gio/tests/contexts.c b/gio/tests/contexts.c
index 60b3d1f10..1410a6242 100644
--- a/gio/tests/contexts.c
+++ b/gio/tests/contexts.c
@@ -186,6 +186,9 @@ main (int argc, char **argv)
   GError *error = NULL;
   int ret;
 
+  /* gvfs leaks like a sieve (mostly on purpose) */
+  g_setenv ("GIO_MODULE_DIR", "/non-existant", TRUE);
+
   g_test_init (&argc, &argv, NULL);
 
   test_file = g_test_build_filename (G_TEST_DIST, "contexts.c", NULL);
diff --git a/gio/tests/converter-stream.c b/gio/tests/converter-stream.c
index f2d45db70..2da0513a5 100644
--- a/gio/tests/converter-stream.c
+++ b/gio/tests/converter-stream.c
@@ -1188,6 +1188,9 @@ main (int   argc,
 
   gint i;
 
+  /* We're testing glib, not other (leaky) stuff */
+  g_setenv ("GIO_MODULE_DIR", "/non-existant", TRUE);
+
   g_test_init (&argc, &argv, NULL);
 
   g_test_bug_base ("http://bugzilla.gnome.org/");
diff --git a/gio/tests/g-file.c b/gio/tests/g-file.c
index 9e3a6331a..1c8290ea6 100644
--- a/gio/tests/g-file.c
+++ b/gio/tests/g-file.c
@@ -508,6 +508,8 @@ main (int   argc,
 {
   g_test_init (&argc, &argv, NULL);
   
+  /* We're testing glib, not other (leaky) stuff */
+  g_setenv ("GIO_MODULE_DIR", "/non-existant", TRUE);
   
   /*  Testing whether g_file_new_for_path() or g_file_new_for_uri() always returns non-NULL result  */
   g_test_add_func ("/g-file/test_g_file_new_null", test_g_file_new_null);
diff --git a/gio/tests/g-icon.c b/gio/tests/g-icon.c
index 598ae94b8..e78061363 100644
--- a/gio/tests/g-icon.c
+++ b/gio/tests/g-icon.c
@@ -586,6 +586,9 @@ int
 main (int   argc,
       char *argv[])
 {
+  /* We're testing glib, not other (leaky) stuff */
+  g_setenv ("GIO_MODULE_DIR", "/non-existant", TRUE);
+
   g_test_init (&argc, &argv, NULL);
 
   g_test_add_func ("/icons/to-string", test_g_icon_to_string);
diff --git a/gio/tests/monitor.c b/gio/tests/monitor.c
index 67be3a440..d65f777bc 100644
--- a/gio/tests/monitor.c
+++ b/gio/tests/monitor.c
@@ -176,6 +176,9 @@ test_directory_monitor (void)
 int
 main (int argc, char *argv[])
 {
+  /* We're testing glib, not other (leaky) stuff */
+  g_setenv ("GIO_MODULE_DIR", "/non-existant", TRUE);
+
   g_test_init (&argc, &argv, NULL);
 
   g_test_add_func ("/monitor/directory", test_directory_monitor);
diff --git a/gio/tests/network-monitor.c b/gio/tests/network-monitor.c
index 618b5e00e..3674f3928 100644
--- a/gio/tests/network-monitor.c
+++ b/gio/tests/network-monitor.c
@@ -520,6 +520,9 @@ main (int argc, char **argv)
       return 0;
     }
 
+  /* We're testing glib, not other (leaky) stuff */
+  g_setenv ("GIO_MODULE_DIR", "/non-existant", TRUE);
+
   g_test_init (&argc, &argv, NULL);
 
   init_test (&net127);