diff --git a/python/lsst/pex/config/callStack.py b/python/lsst/pex/config/callStack.py
index 218ae0f..cd1a91e 100644
--- a/python/lsst/pex/config/callStack.py
+++ b/python/lsst/pex/config/callStack.py
@@ -102,7 +102,7 @@ class StackFrame:
     getStackFrame
     """
 
-    _STRIP = "/python/lsst/"
+    _STRIP = "/python/"
     """String to strip from the ``filename`` in the constructor."""
 
     def __init__(self, filename, lineno, function, content=None):
diff --git a/python/lsst/pex/config/config.py b/python/lsst/pex/config/config.py
index 26d07e9..4a8e740 100644
--- a/python/lsst/pex/config/config.py
+++ b/python/lsst/pex/config/config.py
@@ -321,7 +321,7 @@ def __init__(self, field, config, msg):
         error = (
             f"{self.fieldType.__name__} '{self.fullname}' failed validation: {msg}\n"
             f"For more information see the Field definition at:\n{self.fieldSource.format()}"
-            f" and the Config definition at:\n{self.configSource.format()}"
+            f" and the Config definition for {_typeStr(config)} at:\n{self.configSource.format()}"
         )
         super().__init__(error)