diff --git a/glib/tests/meson.build b/glib/tests/meson.build
index df0d9f8dd..d16a071e5 100644
--- a/glib/tests/meson.build
+++ b/glib/tests/meson.build
@@ -231,15 +231,11 @@ if installed_tests_enabled
   install_subdir('time-zones', install_dir : installed_tests_execdir)
 endif
 
-# Not entirely random of course, but at least it changes over time
-random_number = minor_version + meson.version().split('.').get(1).to_int()
-
 test_env = environment()
 test_env.set('G_TEST_SRCDIR', meson.current_source_dir())
 test_env.set('G_TEST_BUILDDIR', meson.current_build_dir())
 test_env.set('G_DEBUG', 'gc-friendly')
 test_env.set('MALLOC_CHECK_', '2')
-test_env.set('MALLOC_PERTURB_', '@0@'.format(random_number % 256))
 
 test_deps = [libm, thread_dep, libglib_dep]
 test_cargs = ['-DG_LOG_DOMAIN="GLib"', '-UG_DISABLE_ASSERT']
diff --git a/gmodule/tests/meson.build b/gmodule/tests/meson.build
index 1650fe5e0..ad1893b90 100644
--- a/gmodule/tests/meson.build
+++ b/gmodule/tests/meson.build
@@ -41,7 +41,6 @@ test_env.set('G_TEST_SRCDIR', meson.current_source_dir())
 test_env.set('G_TEST_BUILDDIR', meson.current_build_dir())
 test_env.set('G_DEBUG', 'gc-friendly')
 test_env.set('MALLOC_CHECK_', '2')
-test_env.set('MALLOC_PERTURB_', '@0@'.format(random_number % 256))
 
 test_deps = [libm, thread_dep, libglib_dep, libgmodule_dep]
 test_cargs = ['-DG_LOG_DOMAIN="GModule"', '-UG_DISABLE_ASSERT']
diff --git a/gobject/tests/meson.build b/gobject/tests/meson.build
index 84132518a..c5e28b0a0 100644
--- a/gobject/tests/meson.build
+++ b/gobject/tests/meson.build
@@ -109,15 +109,11 @@ python_tests = [
 ]
 
 # FIXME: put common bits of test environment() in one location
-# Not entirely random of course, but at least it changes over time
-random_number = minor_version + meson.version().split('.').get(1).to_int()
-
 test_env = environment()
 test_env.set('G_TEST_SRCDIR', meson.current_source_dir())
 test_env.set('G_TEST_BUILDDIR', meson.current_build_dir())
 test_env.set('G_DEBUG', 'gc-friendly')
 test_env.set('MALLOC_CHECK_', '2')
-test_env.set('MALLOC_PERTURB_', '@0@'.format(random_number % 256))
 
 test_deps = [libm, thread_dep, libglib_dep, libgobject_dep]
 test_cargs = ['-DG_LOG_DOMAIN="GLib-GObject"', '-UG_DISABLE_ASSERT']
diff --git a/tests/meson.build b/tests/meson.build
index 9fd1ab121..c2d927854 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -1,14 +1,10 @@
 # tests
 
-# Not entirely random of course, but at least it changes over time
-random_number = minor_version + meson.version().split('.').get(1).to_int()
-
 test_env = environment()
 test_env.set('G_TEST_SRCDIR', meson.current_source_dir())
 test_env.set('G_TEST_BUILDDIR', meson.current_build_dir())
 test_env.set('G_DEBUG', 'gc-friendly')
 test_env.set('MALLOC_CHECK_', '2')
-test_env.set('MALLOC_PERTURB_', '@0@'.format(random_number % 256))
 
 test_cargs = ['-DG_LOG_DOMAIN="GLib"', '-UG_DISABLE_ASSERT']