diff --git a/poetry/core/json/schemas/poetry-schema.json b/poetry/core/json/schemas/poetry-schema.json
index 708e000f8..519f7b9be 100644
--- a/poetry/core/json/schemas/poetry-schema.json
+++ b/poetry/core/json/schemas/poetry-schema.json
@@ -19,7 +19,8 @@
     },
     "description": {
       "type": "string",
-      "description": "Short package description."
+      "description": "Short package description.",
+      "pattern": "^[^\n]*$"
     },
     "keywords": {
       "type": "array",
diff --git a/tests/json/test_poetry_schema.py b/tests/json/test_poetry_schema.py
index 905427eb1..e414f7f9d 100644
--- a/tests/json/test_poetry_schema.py
+++ b/tests/json/test_poetry_schema.py
@@ -42,3 +42,12 @@ def test_path_dependencies(base_object):
 
 def test_multi_url_dependencies(multi_url_object):
     assert len(validate_object(multi_url_object, "poetry-schema")) == 0
+
+
+def test_multiline_description(base_object):
+    bad_description = "Some multi-\nline string"
+    base_object["description"] = bad_description
+
+    errors = validate_object(base_object, "poetry-schema")
+    assert len(errors) == 1
+    assert errors[0] == "[description] %r does not match '^[^\\n]*$'" % bad_description