diff --git a/bindings/python-cffi/notmuch2/_build.py b/bindings/python-cffi/notmuch2/_build.py
index 45eb20c0..a55b484f 100644
--- a/bindings/python-cffi/notmuch2/_build.py
+++ b/bindings/python-cffi/notmuch2/_build.py
@@ -54,6 +54,7 @@ ffibuilder.cdef(
         NOTMUCH_STATUS_NO_DATABASE,
         NOTMUCH_STATUS_DATABASE_EXISTS,
         NOTMUCH_STATUS_BAD_QUERY_SYNTAX,
+        NOTMUCH_STATUS_NO_MAIL_ROOT,
         NOTMUCH_STATUS_LAST_STATUS
     } notmuch_status_t;
     typedef enum {
diff --git a/lib/config.cc b/lib/config.cc
index 8f6ef110..f61eb636 100644
--- a/lib/config.cc
+++ b/lib/config.cc
@@ -657,6 +657,7 @@ notmuch_status_t
 _notmuch_config_load_defaults (notmuch_database_t *notmuch)
 {
     notmuch_config_key_t key;
+    notmuch_status_t status = NOTMUCH_STATUS_SUCCESS;
 
     if (notmuch->config == NULL)
 	notmuch->config = _notmuch_string_map_create (notmuch);
@@ -669,11 +670,14 @@ _notmuch_config_load_defaults (notmuch_database_t *notmuch)
 
 	val = _notmuch_string_map_get (notmuch->config, key_string);
 	if (! val) {
+	    if (key == NOTMUCH_CONFIG_MAIL_ROOT && (notmuch->params & NOTMUCH_PARAM_SPLIT))
+		status = NOTMUCH_STATUS_NO_MAIL_ROOT;
+
 	    _notmuch_string_map_set (notmuch->config, key_string, _notmuch_config_default (notmuch,
 											   key));
 	}
     }
-    return NOTMUCH_STATUS_SUCCESS;
+    return status;
 }
 
 const char *
diff --git a/lib/database.cc b/lib/database.cc
index 6ef56d56..0effe978 100644
--- a/lib/database.cc
+++ b/lib/database.cc
@@ -311,6 +311,8 @@ notmuch_status_to_string (notmuch_status_t status)
 	return "Database exists, not recreated";
     case NOTMUCH_STATUS_BAD_QUERY_SYNTAX:
 	return "Syntax error in query";
+    case NOTMUCH_STATUS_NO_MAIL_ROOT:
+	return "No mail root found";
     default:
     case NOTMUCH_STATUS_LAST_STATUS:
 	return "Unknown error status value";
diff --git a/lib/notmuch.h b/lib/notmuch.h
index 1b2bdf3f..fef98b4b 100644
--- a/lib/notmuch.h
+++ b/lib/notmuch.h
@@ -224,6 +224,10 @@ typedef enum {
      * Syntax error in query
      */
     NOTMUCH_STATUS_BAD_QUERY_SYNTAX,
+    /**
+     * No mail root could be deduced from parameters and environment
+     */
+    NOTMUCH_STATUS_NO_MAIL_ROOT,
     /**
      * Not an actual status value. Just a way to find out how many
      * valid status values there are.
diff --git a/test/T590-libconfig.sh b/test/T590-libconfig.sh
index 9cc79e8c..0b5291ab 100755
--- a/test/T590-libconfig.sh
+++ b/test/T590-libconfig.sh
@@ -1022,7 +1022,6 @@ notmuch_dir_sanitize < OUTPUT > OUTPUT.clean
 test_expect_equal_file EXPECTED.common OUTPUT.clean
 
 test_begin_subtest "open/error: config=empty with no mail root in db (xdg)"
-test_subtest_known_broken
 old_NOTMUCH_CONFIG=${NOTMUCH_CONFIG}
 unset NOTMUCH_CONFIG
 backup_database