diff --git a/src/lint/linter/ArcanistPyLintLinter.php b/src/lint/linter/ArcanistPyLintLinter.php
--- a/src/lint/linter/ArcanistPyLintLinter.php
+++ b/src/lint/linter/ArcanistPyLintLinter.php
@@ -130,10 +130,15 @@
         continue;
       }
 
+      // NOTE: PyLint sometimes returns -1 as the character offset for a
+      // message. If it does, treat it as 0. See T9257.
+      $char = (int)$matches[1];
+      $char = max(0, $char);
+
       $message = id(new ArcanistLintMessage())
         ->setPath($path)
         ->setLine($matches[0])
-        ->setChar($matches[1])
+        ->setChar($char)
         ->setCode($matches[2])
         ->setSeverity($this->getLintMessageSeverity($matches[2]))
         ->setName(ucwords(str_replace('-', ' ', $matches[3])))
diff --git a/src/lint/linter/__tests__/pylint/negativechar.lint-test b/src/lint/linter/__tests__/pylint/negativechar.lint-test
new file mode 100644
--- /dev/null
+++ b/src/lint/linter/__tests__/pylint/negativechar.lint-test
@@ -0,0 +1,6 @@
+"""Docstring"""
+
+"""
+Useless string """
+~~~~~~~~~~
+warning:4:0 See T9257.
diff --git a/src/lint/linter/__tests__/xml/languages-7.lint-test b/src/lint/linter/__tests__/xml/languages-7.lint-test
deleted file mode 100644
--- a/src/lint/linter/__tests__/xml/languages-7.lint-test
+++ /dev/null
@@ -1,7 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<languages>
-    <lang>
-</languages>
-~~~~~~~~~~
-error:4:7
-error:5:1