diff --git a/CHANGES.md b/CHANGES.md
index 7e251c8..3e0ef36 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -7,7 +7,8 @@ Known issues:
 
 ## not yet released
 
-(nothing yet)
+- Ensure that `bunyan` errors out if attempting to use `-p PID` and
+  file args at the same time.
 
 
 ## 1.8.9
diff --git a/bin/bunyan b/bin/bunyan
index 1ff7c12..9c1595c 100755
--- a/bin/bunyan
+++ b/bin/bunyan
@@ -1525,9 +1525,9 @@ function main(argv) {
         console.log('bunyan ' + getVersion());
         return;
     }
-    if (opts.pid && opts.args.length > 0) {
+    if (opts.pids && opts.args.length > 0) {
         warn('bunyan: error: can\'t use both "-p PID" (%s) and file (%s) args',
-            opts.pid, opts.args.join(' '));
+            opts.pids, opts.args.join(' '));
         return drainStdoutAndExit(1);
     }
     if (opts.color === null) {