diff --git a/crates/ruff_linter/resources/test/fixtures/pylint/unspecified_encoding.py b/crates/ruff_linter/resources/test/fixtures/pylint/unspecified_encoding.py
index fca823bcbc..db89cbf4e2 100644
--- a/crates/ruff_linter/resources/test/fixtures/pylint/unspecified_encoding.py
+++ b/crates/ruff_linter/resources/test/fixtures/pylint/unspecified_encoding.py
@@ -94,3 +94,6 @@ Path("foo.txt").write_text(text, **kwargs)
 # Violation but not detectable
 x = Path("foo.txt")
 x.open()
+
+# https://github.com/astral-sh/ruff/issues/18107
+codecs.open("plw1514.py", "r", "utf-8").close() # this is fine
diff --git a/crates/ruff_linter/src/rules/pylint/rules/unspecified_encoding.rs b/crates/ruff_linter/src/rules/pylint/rules/unspecified_encoding.rs
index 66a44e0fd7..9f49c5beae 100644
--- a/crates/ruff_linter/src/rules/pylint/rules/unspecified_encoding.rs
+++ b/crates/ruff_linter/src/rules/pylint/rules/unspecified_encoding.rs
@@ -215,8 +215,18 @@ fn is_violation(call: &ast::ExprCall, qualified_name: &Callee) -> bool {
                         return false;
                     }
                 }
+
+                let encoding_param_pos = match qualified_name.segments() {
+                    // The `encoding` parameter position for `codecs.open`
+                    ["codecs", _] => 2,
+                    // The `encoding` parameter position for `_io.open` and the builtin `open`
+                    _ => 3,
+                };
+
                 // else mode not specified, defaults to text mode
-                call.arguments.find_argument_value("encoding", 3).is_none()
+                call.arguments
+                    .find_argument_value("encoding", encoding_param_pos)
+                    .is_none()
             }
             ["tempfile", tempfile_class @ ("TemporaryFile" | "NamedTemporaryFile" | "SpooledTemporaryFile")] =>
             {