diff --git a/pytest_mypy_plugins/tests/test-regex-assertions.yml b/pytest_mypy_plugins/tests/test-regex-assertions.yml
index c16e5d7..2e8806b 100644
--- a/pytest_mypy_plugins/tests/test-regex-assertions.yml
+++ b/pytest_mypy_plugins/tests/test-regex-assertions.yml
@@ -54,3 +54,18 @@
   main: |
     a = 'hello'
     reveal_type(a)  # NR: .*banana.*
+
+- case: regex_against_callable_comment
+  main: |
+    def foo(bar: str, ham: int = 42) -> set[str | int]:
+      return {bar, ham}
+    reveal_type(foo)  # NR: Revealed type is "def \(bar: builtins\.str, ham: builtins\.int =\) -> .*"
+
+- case: regex_against_callable_out
+  regex: yes
+  main: |
+    def foo(bar: str, ham: int = 42) -> set[str | int]:
+      return {bar, ham}
+    reveal_type(foo)
+  out: |
+    main:3: note: Revealed type is "def \(bar: builtins\.str, ham: builtins\.int =\) -> .*"
diff --git a/pytest_mypy_plugins/utils.py b/pytest_mypy_plugins/utils.py
index 6eb3d1f..d755508 100644
--- a/pytest_mypy_plugins/utils.py
+++ b/pytest_mypy_plugins/utils.py
@@ -326,7 +326,7 @@ def extract_output_matchers_from_out(out: str, params: Mapping[str, Any], regex:
     lines = render_template(out, params).split("\n")
     for line in lines:
         match = re.search(
-            r"^(?P<fname>.*):(?P<lnum>\d*): (?P<severity>.*):((?P<col>\d+):)? (?P<message>.*)$", line.strip()
+            r"^(?P<fname>.+):(?P<lnum>\d+): (?P<severity>[A-Za-z]+):((?P<col>\d+):)? (?P<message>.*)$", line.strip()
         )
         if match:
             if match.group("severity") == "E":