diff --git a/frontend/src/scenes/data-warehouse/external/forms/sourceFormLogic.ts b/frontend/src/scenes/data-warehouse/external/forms/sourceFormLogic.ts
index b49520c71fa67..1bca52f3bffbf 100644
--- a/frontend/src/scenes/data-warehouse/external/forms/sourceFormLogic.ts
+++ b/frontend/src/scenes/data-warehouse/external/forms/sourceFormLogic.ts
@@ -84,6 +84,9 @@ export const sourceFormLogic = kea<sourceFormLogicType>([
         submitExternalDataSourceFailure: ({ error }) => {
             lemonToast.error(error?.message || 'Something went wrong')
         },
+        submitDatabaseSchemaFormFailure: ({ error }) => {
+            lemonToast.error(error?.message || 'Something went wrong')
+        },
         handleRedirect: async ({ kind, searchParams }) => {
             switch (kind) {
                 case 'hubspot': {
diff --git a/posthog/warehouse/api/external_data_source.py b/posthog/warehouse/api/external_data_source.py
index 6078e9d8cd6da..faf884d6c8b3b 100644
--- a/posthog/warehouse/api/external_data_source.py
+++ b/posthog/warehouse/api/external_data_source.py
@@ -341,7 +341,15 @@ def database_schema(self, request: Request, *arg: Any, **kwargs: Any):
                 data={"message": "Cannot use internal Postgres database"},
             )
 
-        result = get_postgres_schemas(host, port, database, user, password, schema)
+        try:
+            result = get_postgres_schemas(host, port, database, user, password, schema)
+        except Exception as e:
+            logger.exception("Could not fetch Postgres schemas", exc_info=e)
+            return Response(
+                status=status.HTTP_400_BAD_REQUEST,
+                data={"message": "Could not fetch Postgres schemas. Please check all connection details are valid."},
+            )
+
         result_mapped_to_options = [{"table": row, "should_sync": False} for row in result]
         return Response(status=status.HTTP_200_OK, data=result_mapped_to_options)