diff --git a/procprof/make_example_images.py b/procprof/make_example_images.py
index 0e8d0ab..72904b1 100755
--- a/procprof/make_example_images.py
+++ b/procprof/make_example_images.py
@@ -18,7 +18,7 @@ from sfdata import SFDataFiles
 FPIC = ":FPICTURE"
 
 
-def main(fn_input, fn_output, camera, nimages)
+def main(fn_input, fn_output, camera, nimages):
     if fn_input is None:
         imgs = mk_rand(nimages)
     else: