diff --git a/src/_pytest/assertion/__init__.py b/src/_pytest/assertion/__init__.py
index ad2454ab820..2644ab51bae 100644
--- a/src/_pytest/assertion/__init__.py
+++ b/src/_pytest/assertion/__init__.py
@@ -51,11 +51,13 @@ def pytest_addoption(parser: Parser) -> None:
 
     parser.addini(
         "truncation_limit_lines",
+        type="int",
         default=None,
         help="Set threshold of LINES after which truncation will take effect",
     )
     parser.addini(
         "truncation_limit_chars",
+        type="int",
         default=None,
         help=("Set threshold of CHARS after which truncation will take effect"),
     )