diff --git a/CHANGELOG.md b/CHANGELOG.md
index d8c4473a3..cd34e3bfb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,7 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixes
 - Relative paths are now allowed in securitySchemes/OAuthFlow/tokenUrl (#130).
 - Schema validation errors will no longer print a stack trace (#131).
-
+- Invalid YAML/URL will no longer print stack trace (#128)
 
 ## 0.5.0 - 2020-08-05
 ### Changes
diff --git a/openapi_python_client/__init__.py b/openapi_python_client/__init__.py
index 0b753c5fc..4650d6295 100644
--- a/openapi_python_client/__init__.py
+++ b/openapi_python_client/__init__.py
@@ -7,6 +7,7 @@
 from pathlib import Path
 from typing import Any, Dict, Optional, Sequence, Union
 
+import httpcore
 import httpx
 import yaml
 from jinja2 import Environment, PackageLoader
@@ -27,6 +28,8 @@
 
 def _get_project_for_url_or_path(url: Optional[str], path: Optional[Path]) -> Union[_Project, GeneratorError]:
     data_dict = _get_document(url=url, path=path)
+    if isinstance(data_dict, GeneratorError):
+        return data_dict
     openapi = GeneratorData.from_dict(data_dict)
     if isinstance(openapi, GeneratorError):
         return openapi
@@ -70,18 +73,24 @@ def update_existing_client(*, url: Optional[str], path: Optional[Path]) -> Seque
     return project.update()
 
 
-def _get_document(*, url: Optional[str], path: Optional[Path]) -> Dict[str, Any]:
+def _get_document(*, url: Optional[str], path: Optional[Path]) -> Union[Dict[str, Any], GeneratorError]:
     yaml_bytes: bytes
     if url is not None and path is not None:
-        raise ValueError("Provide URL or Path, not both.")
+        return GeneratorError(header="Provide URL or Path, not both.")
     if url is not None:
-        response = httpx.get(url)
-        yaml_bytes = response.content
+        try:
+            response = httpx.get(url)
+            yaml_bytes = response.content
+        except (httpx.HTTPError, httpcore.NetworkError):
+            return GeneratorError(header="Could not get OpenAPI document from provided URL")
     elif path is not None:
         yaml_bytes = path.read_bytes()
     else:
-        raise ValueError("No URL or Path provided")
-    return yaml.safe_load(yaml_bytes)
+        return GeneratorError(header="No URL or Path provided")
+    try:
+        return yaml.safe_load(yaml_bytes)
+    except yaml.YAMLError:
+        return GeneratorError(header="Invalid YAML from provided source")
 
 
 class _Project:
diff --git a/tests/test___init__.py b/tests/test___init__.py
index 809dd40ba..1700d638a 100644
--- a/tests/test___init__.py
+++ b/tests/test___init__.py
@@ -1,7 +1,9 @@
 import pathlib
 
+import httpcore
 import jinja2
 import pytest
+import yaml
 
 from openapi_python_client import GeneratorError
 
@@ -44,6 +46,23 @@ def test__get_project_for_url_or_path_generator_error(mocker):
     assert project == error
 
 
+def test__get_project_for_url_or_path_document_error(mocker):
+    error = GeneratorError()
+    _get_document = mocker.patch("openapi_python_client._get_document", return_value=error)
+
+    from_dict = mocker.patch("openapi_python_client.parser.GeneratorData.from_dict")
+    url = mocker.MagicMock()
+    path = mocker.MagicMock()
+
+    from openapi_python_client import _get_project_for_url_or_path
+
+    project = _get_project_for_url_or_path(url=url, path=path)
+
+    _get_document.assert_called_once_with(url=url, path=path)
+    from_dict.assert_not_called()
+    assert project == error
+
+
 def test_create_new_client(mocker):
     project = mocker.MagicMock()
     _get_project_for_url_or_path = mocker.patch(
@@ -118,9 +137,9 @@ def test__get_document_no_url_or_path(self, mocker):
 
         from openapi_python_client import _get_document
 
-        with pytest.raises(ValueError):
-            _get_document(url=None, path=None)
+        result = _get_document(url=None, path=None)
 
+        assert result == GeneratorError(header="No URL or Path provided")
         get.assert_not_called()
         Path.assert_not_called()
         loads.assert_not_called()
@@ -132,13 +151,28 @@ def test__get_document_url_and_path(self, mocker):
 
         from openapi_python_client import _get_document
 
-        with pytest.raises(ValueError):
-            _get_document(url=mocker.MagicMock(), path=mocker.MagicMock())
+        result = _get_document(url=mocker.MagicMock(), path=mocker.MagicMock())
 
+        assert result == GeneratorError(header="Provide URL or Path, not both.")
         get.assert_not_called()
         Path.assert_not_called()
         loads.assert_not_called()
 
+    def test__get_document_bad_url(self, mocker):
+        get = mocker.patch("httpx.get", side_effect=httpcore.NetworkError)
+        Path = mocker.patch("openapi_python_client.Path")
+        loads = mocker.patch("yaml.safe_load")
+
+        from openapi_python_client import _get_document
+
+        url = mocker.MagicMock()
+        result = _get_document(url=url, path=None)
+
+        assert result == GeneratorError(header="Could not get OpenAPI document from provided URL")
+        get.assert_called_once_with(url)
+        Path.assert_not_called()
+        loads.assert_not_called()
+
     def test__get_document_url_no_path(self, mocker):
         get = mocker.patch("httpx.get")
         Path = mocker.patch("openapi_python_client.Path")
@@ -166,6 +200,20 @@ def test__get_document_path_no_url(self, mocker):
         path.read_bytes.assert_called_once()
         loads.assert_called_once_with(path.read_bytes())
 
+    def test__get_document_bad_yaml(self, mocker):
+        get = mocker.patch("httpx.get")
+        loads = mocker.patch("yaml.safe_load", side_effect=yaml.YAMLError)
+
+        from openapi_python_client import _get_document
+
+        path = mocker.MagicMock()
+        result = _get_document(url=None, path=path)
+
+        get.assert_not_called()
+        path.read_bytes.assert_called_once()
+        loads.assert_called_once_with(path.read_bytes())
+        assert result == GeneratorError(header="Invalid YAML from provided source")
+
 
 class TestProject:
     def test___init__(self, mocker):