diff --git a/mara_dbt/commands.py b/mara_dbt/commands.py
index 3c0c7ec..0653f9b 100644
--- a/mara_dbt/commands.py
+++ b/mara_dbt/commands.py
@@ -29,6 +29,7 @@ def shell_command(self):
             variables.update(self.variables)
 
         return (f'dbt --no-use-colors {self._dbt_command}'
+                + (f' --project-dir {config.project_dir()}' if config.project_dir() else '')
                 + (f' --profiles-dir {config.profiles_dir()}' if config.profiles_dir() else '')
                 + (f' --profile {config.profile()}' if config.profile() else '')
                 + (f' -t {self.target}' if self.target else '')
diff --git a/mara_dbt/config.py b/mara_dbt/config.py
index 9753385..fb017b5 100644
--- a/mara_dbt/config.py
+++ b/mara_dbt/config.py
@@ -1,7 +1,9 @@
 import pathlib
+import os
+from typing import Optional
 
 
-def dbt_target() -> str:
+def dbt_target() -> Optional[str]:
     """
     The dbt default target to be used.
     
@@ -24,21 +26,21 @@ def dbt_variables() -> dict:
     return {}
 
 
-def dbt_cloud_host() -> str:
+def dbt_cloud_host() -> Optional[str]:
     """
     dbt Cloud host (cloud.getdbt.com (multi-tenant instance) by default if the environment variable is not set)
     """
     return None
 
 
-def dbt_cloud_api_token() -> str:
+def dbt_cloud_api_token() -> Optional[str]:
     """
     API authentication key
     """
     return None
 
 
-def dbt_cloud_account_id() -> str:
+def dbt_cloud_account_id() -> Optional[str]:
     """
     Numeric ID of the dbt Cloud account
     """
@@ -49,20 +51,28 @@ def dbt_cloud_account_id() -> str:
 # Advanced config 
 # -----------------------------------------------------------------------------
 
-def profiles_dir() -> str:
+def profiles_dir() -> Optional[str]:
     """ The folder in which the dbt profiles are saved. If None, ~/.dbt/ is used (dbt default) """
     return None
 
-def profile() -> str:
+
+def profile() -> Optional[str]:
     """ Which dbt profile to use. If not set the default profile will be used """
     return None
 
 
+def project_dir() -> Optional[str]:
+    """ If a custom project path shall be used. This is read from environment variable DBT_PROJECT_DIR. """
+    # Use env. to support https://github.com/dbt-labs/dbt-core/issues/6078. Can be dropped when minimum
+    # dbt version for this module is a version which supports dbt-core#6078.
+    return os.environ.get('DBT_PROJECT_DIR')
+
+
 # -----------------------------------------------------------------------------
 # Experimental, building dbt via the mara project
 # -----------------------------------------------------------------------------
 
-def schema_name() -> str:
+def schema_name() -> Optional[str]:
     """ The schema name which shall be used in the config. If not set, the default db schema will be used. """
     return None