diff --git a/gio/tests/g-file-info-filesystem-readonly.c b/gio/tests/g-file-info-filesystem-readonly.c
index e4af3045f..fbe122e72 100644
--- a/gio/tests/g-file-info-filesystem-readonly.c
+++ b/gio/tests/g-file-info-filesystem-readonly.c
@@ -96,7 +96,8 @@ test_filesystem_readonly (gconstpointer with_mount_monitor)
   GFile *mounted_file;
   GUnixMountMonitor *mount_monitor = NULL;
   gchar *bindfs, *fusermount;
-  gchar *curdir, *dir_to_mount, *dir_mountpoint;
+  const char *curdir;
+  char *dir_to_mount = NULL, *dir_mountpoint = NULL;
   gchar *file_in_mount, *file_in_mountpoint;
   GError *error = NULL;
 
@@ -127,7 +128,7 @@ test_filesystem_readonly (gconstpointer with_mount_monitor)
       return;
     }
 
-  curdir = g_get_current_dir ();
+  curdir = g_get_tmp_dir ();
   dir_to_mount = g_build_filename (curdir, "dir_bindfs_to_mount", NULL);
   file_in_mount = g_build_filename (dir_to_mount, "example.txt", NULL);
   dir_mountpoint = g_build_filename (curdir, "dir_bindfs_mountpoint", NULL);
@@ -141,7 +142,6 @@ test_filesystem_readonly (gconstpointer with_mount_monitor)
       g_free (dir_mountpoint);
       g_free (file_in_mount);
       g_free (dir_to_mount);
-      g_free (curdir);
       g_free (fusermount);
       g_free (bindfs);
       return;
@@ -164,7 +164,6 @@ test_filesystem_readonly (gconstpointer with_mount_monitor)
       g_free (dir_mountpoint);
       g_free (file_in_mount);
       g_free (dir_to_mount);
-      g_free (curdir);
       g_free (fusermount);
       g_free (bindfs);
 
@@ -197,7 +196,6 @@ test_filesystem_readonly (gconstpointer with_mount_monitor)
       g_free (dir_mountpoint);
       g_free (file_in_mount);
       g_free (dir_to_mount);
-      g_free (curdir);
       g_free (fusermount);
       g_free (bindfs);
 
@@ -241,7 +239,6 @@ test_filesystem_readonly (gconstpointer with_mount_monitor)
 
   g_free (bindfs);
   g_free (fusermount);
-  g_free (curdir);
   g_free (dir_to_mount);
   g_free (dir_mountpoint);
   g_free (file_in_mount);
@@ -254,7 +251,7 @@ main (int argc, char *argv[])
   /* To avoid unnecessary D-Bus calls, see http://goo.gl/ir56j2 */
   g_setenv ("GIO_USE_VFS", "local", FALSE);
 
-  g_test_init (&argc, &argv, NULL);
+  g_test_init (&argc, &argv, G_TEST_OPTION_ISOLATE_DIRS, NULL);
 
   g_test_bug ("https://bugzilla.gnome.org/show_bug.cgi?id=787731");
 
diff --git a/gio/tests/gsettings.c b/gio/tests/gsettings.c
index d7afeee53..60f2aebae 100644
--- a/gio/tests/gsettings.c
+++ b/gio/tests/gsettings.c
@@ -3289,7 +3289,7 @@ main (int argc, char *argv[])
 
   setlocale (LC_ALL, "");
 
-  g_test_init (&argc, &argv, NULL);
+  g_test_init (&argc, &argv, G_TEST_OPTION_ISOLATE_DIRS, NULL);
 
   if (!g_test_subprocess ())
     {
diff --git a/gio/tests/live-g-file.c b/gio/tests/live-g-file.c
index e10390027..c96f9db94 100644
--- a/gio/tests/live-g-file.c
+++ b/gio/tests/live-g-file.c
@@ -32,8 +32,6 @@
 #include <string.h>
 #include <sys/stat.h>
 
-#define DEFAULT_TEST_DIR		"testdir_live-g-file"
-
 #define PATTERN_FILE_SIZE	0x10000
 #define TEST_HANDLE_SPECIAL	TRUE
 
@@ -1342,9 +1340,10 @@ int
 main (int argc, char *argv[])
 {
   static gboolean only_create_struct;
-  const char *target_path;
+  char *target_path = NULL;
   GError *error;
   GOptionContext *context;
+  int retval;
 
   static GOptionEntry cmd_entries[] = {
     {"read-write", 'w', 0, G_OPTION_ARG_NONE, &write_test,
@@ -1365,7 +1364,7 @@ main (int argc, char *argv[])
   posix_compat = FALSE;
 
   /*  strip all gtester-specific args  */
-  g_test_init (&argc, &argv, NULL);
+  g_test_init (&argc, &argv, G_TEST_OPTION_ISOLATE_DIRS, NULL);
 
   /*  no extra parameters specified, assume we're executed from glib test suite  */ 
   if (argc < 2)
@@ -1374,7 +1373,7 @@ main (int argc, char *argv[])
 	  verbose = TRUE;
 	  write_test = TRUE;
 	  only_create_struct = FALSE;
-	  target_path = DEFAULT_TEST_DIR;
+	  target_path = g_build_filename (g_get_tmp_dir (), "testdir_live-g-file", NULL);
 #ifdef G_PLATFORM_WIN32
 	  posix_compat = FALSE;
 #else
@@ -1394,7 +1393,7 @@ main (int argc, char *argv[])
 
   /*  remaining arg should is the target path; we don't care of the extra args here  */ 
   if (argc >= 2)
-    target_path = strdup (argv[1]);
+    target_path = g_strdup (argv[1]);
   
   if (! target_path) 
     {
@@ -1471,6 +1470,9 @@ main (int argc, char *argv[])
     g_test_add_data_func ("/live-g-file/final_clean", target_path,
     	  	  prep_clean_structure);
 
-  return g_test_run ();
+  retval = g_test_run ();
 
+  g_free (target_path);
+
+  return retval;
 }
diff --git a/glib/tests/bookmarkfile.c b/glib/tests/bookmarkfile.c
index d3038796a..198f261ed 100644
--- a/glib/tests/bookmarkfile.c
+++ b/glib/tests/bookmarkfile.c
@@ -153,6 +153,7 @@ test_corner_cases (void)
   gchar *message, **messages;
   GError *error = NULL;
   GBookmarkFile *bookmark;
+  char *path = NULL;
 
   bookmark = g_bookmark_file_new ();
 
@@ -669,8 +670,10 @@ test_corner_cases (void)
   g_clear_error (&error);
 
   /* g_bookmark_file_to_file() */
-  g_assert_true (g_bookmark_file_to_file (bookmark, "a", &error));
+  path = g_build_filename (g_get_tmp_dir (), "corner-case-bookmark-file.xbel", NULL);
+  g_assert_true (g_bookmark_file_to_file (bookmark, path, &error));
   g_assert_no_error (error);
+  g_free (path);
 
   /* g_bookmark_file_remove_group() */
   g_assert_false (g_bookmark_file_remove_group (bookmark, "a", NULL, NULL));
diff --git a/glib/tests/fileutils.c b/glib/tests/fileutils.c
index a92c896ae..fdc9ce3de 100644
--- a/glib/tests/fileutils.c
+++ b/glib/tests/fileutils.c
@@ -664,7 +664,7 @@ test_build_filenamev (void)
 static void
 test_mkdir_with_parents_1 (const gchar *base)
 {
-  char *p0 = g_build_filename (base, "fum", NULL);
+  char *p0 = g_build_filename (g_get_tmp_dir (), base, "fum", NULL);
   char *p1 = g_build_filename (p0, "tem", NULL);
   char *p2 = g_build_filename (p1, "zap", NULL);
   FILE *f;
@@ -817,6 +817,7 @@ test_mkdir_with_parents (void)
 #ifndef G_OS_WIN32
   gboolean can_override_dac = check_cap_dac_override (NULL);
 #endif
+
   g_test_message ("Checking g_mkdir_with_parents() in subdir ./hum/");
   test_mkdir_with_parents_1 ("hum");
   g_remove ("hum");
@@ -828,9 +829,6 @@ test_mkdir_with_parents (void)
   g_remove ("hii");
 
   cwd = g_get_current_dir ();
-  g_test_message ("Checking g_mkdir_with_parents() in cwd: %s", cwd);
-  test_mkdir_with_parents_1 (cwd);
-
   new_path = g_build_filename (cwd, "new", NULL);
   g_assert_cmpint (g_mkdir_with_parents (new_path, 0), ==, 0);
   g_assert_cmpint (g_rmdir (new_path), ==, 0);
@@ -1445,7 +1443,7 @@ test_get_contents (void)
   gchar *contents;
   GError *error = NULL;
   const gchar *text = "abcdefghijklmnopqrstuvwxyz";
-  const gchar *filename = "file-test-get-contents";
+  char *filename = g_build_filename (g_get_tmp_dir (), "file-test-get-contents", NULL);
   gsize bytes_written;
 
   f = g_fopen (filename, "w");
@@ -1474,6 +1472,7 @@ test_get_contents (void)
 
   g_free (contents);
   g_remove (filename);
+  g_free (filename);
 }
 
 static gboolean
@@ -2196,7 +2195,7 @@ test_stdio_wrappers (void)
 static void
 test_fopen_modes (void)
 {
-  char        *path = g_build_filename ("temp-fopen", NULL);
+  char        *path = g_build_filename (g_get_tmp_dir (), "temp-fopen", NULL);
   gsize        i;
   const gchar *modes[] =
     {
diff --git a/glib/tests/io-channel.c b/glib/tests/io-channel.c
index 99879be1b..cab486932 100644
--- a/glib/tests/io-channel.c
+++ b/glib/tests/io-channel.c
@@ -39,8 +39,10 @@ test_small_writes (void)
   guint bytes_remaining;
   gchar tmp;
   GError *local_error = NULL;
+  char *path = NULL;
 
-  io = g_io_channel_new_file ("iochannel-test-outfile", "w", &local_error);
+  path = g_build_filename (g_get_tmp_dir (), "iochannel-test-outfile", NULL);
+  io = g_io_channel_new_file (path, "w", &local_error);
   g_assert_no_error (local_error);
 
   g_io_channel_set_encoding (io, NULL, NULL);
@@ -61,7 +63,8 @@ test_small_writes (void)
   g_assert_cmpint (status, ==, G_IO_STATUS_NORMAL);
 
   g_io_channel_unref (io);
-  g_remove ("iochannel-test-outfile");
+  g_remove (path);
+  g_free (path);
 }
 
 static void
@@ -70,7 +73,7 @@ test_read_write (void)
   GIOChannel *gio_r, *gio_w ;
   GError *local_error = NULL;
   GString *buffer;
-  char *filename;
+  char *in_path = NULL, *out_path = NULL;
   gint rlength = 0;
   glong wlength = 0;
   gsize length_out;
@@ -78,14 +81,15 @@ test_read_write (void)
   GIOStatus status;
   const gsize buffer_size_bytes = 1024;
 
-  filename = g_test_build_filename (G_TEST_DIST, "iochannel-test-infile", NULL);
+  in_path = g_test_build_filename (G_TEST_DIST, "iochannel-test-infile", NULL);
 
   setbuf (stdout, NULL); /* For debugging */
 
-  gio_r = g_io_channel_new_file (filename, "r", &local_error);
+  gio_r = g_io_channel_new_file (in_path, "r", &local_error);
   g_assert_no_error (local_error);
 
-  gio_w = g_io_channel_new_file ("iochannel-test-outfile", "w", &local_error);
+  out_path = g_build_filename (g_get_tmp_dir (), "iochannel-test-outfile", NULL);
+  gio_w = g_io_channel_new_file (out_path, "w", &local_error);
   g_assert_no_error (local_error);
 
   g_io_channel_set_encoding (gio_r, encoding, &local_error);
@@ -164,7 +168,8 @@ test_read_write (void)
 
   test_small_writes ();
 
-  g_free (filename);
+  g_free (in_path);
+  g_free (out_path);
   g_string_free (buffer, TRUE);
 }
 
@@ -227,7 +232,7 @@ int
 main (int   argc,
       char *argv[])
 {
-  g_test_init (&argc, &argv, NULL);
+  g_test_init (&argc, &argv, G_TEST_OPTION_ISOLATE_DIRS, NULL);
 
   g_test_add_func ("/io-channel/read-write", test_read_write);
   g_test_add_func ("/io-channel/read-line/embedded-nuls", test_read_line_embedded_nuls);