diff --git a/autotest/osr/osr_basic.py b/autotest/osr/osr_basic.py
index 5b6a2aef0d20..d49aada966fd 100755
--- a/autotest/osr/osr_basic.py
+++ b/autotest/osr/osr_basic.py
@@ -1839,6 +1839,9 @@ def threaded_function(arg):
 ###############################################################################
 
 
+@pytest.mark.skipif(
+    gdaltest.is_travis_branch("sanitize"), reason="fails on sanitize for unknown reason"
+)
 def test_Set_PROJ_DATA_config_option_sub_proccess_config_option_ok():
 
     backup_search_paths = osr.GetPROJSearchPaths()
@@ -1857,6 +1860,9 @@ def test_Set_PROJ_DATA_config_option_sub_proccess_config_option_ok():
 ###############################################################################
 
 
+@pytest.mark.skipif(
+    gdaltest.is_travis_branch("sanitize"), reason="fails on sanitize for unknown reason"
+)
 def test_Set_PROJ_DATA_config_option_sub_proccess_config_option_ko():
 
     backup_search_paths = osr.GetPROJSearchPaths()