diff --git a/CHANGES.md b/CHANGES.md
index bf45539..75c91fd 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -8,7 +8,7 @@ Known issues:
 
 ## bunyan 1.3.5 (not yet released)
 
-(nothing yet)
+- [issue #242] Be defensive on err.stack not being a string.
 
 
 ## bunyan 1.3.4
diff --git a/bin/bunyan b/bin/bunyan
index fbf4a8e..e4e387b 100755
--- a/bin/bunyan
+++ b/bin/bunyan
@@ -976,7 +976,11 @@ function emitRecord(rec, line, opts, stylize) {
 
         if (rec.err && rec.err.stack) {
             var err = rec.err
-            details.push(indent(err.stack));
+            if (typeof (err.stack) !== 'string') {
+                details.push(indent(err.stack.toString()));
+            } else {
+                details.push(indent(err.stack));
+            }
             delete err.message;
             delete err.name;
             delete err.stack;