diff --git a/htdocs/- b/htdocs/-
index 05512888d192d32f84ce4036d6986c9bd9ee8df8..4510990863599990507337cb8d503cec2378f6f9 100755
--- a/htdocs/-
+++ b/htdocs/-
@@ -6,10 +6,15 @@ import os.path
 import sys
 from wsgiref.handlers import CGIHandler
 
-if __name__ == '__main__':
-    # Move to project directory.
-    os.chdir('..')
-    sys.path[0] = os.path.abspath('.')
+# Move to project directory.
+os.chdir('..')
+sys.path[0] = os.path.abspath('.')
 
-    from visualizer import app
-    CGIHandler().run(app)
+# Activate the virtual environment to give visualizer.py access to
+# non-standard packages.
+activator = 'venv/bin/activate_this.py'
+exec(open(activator).read(), {'__file__': activator})
+
+# Run the app as CGI.
+from visualizer import app
+CGIHandler().run(app)
diff --git a/visualizer.py b/visualizer.py
index b0352130f983db1fe637ded82b81c0da51d500ef..dd588e81e31581aa0a74ab52f9d81b2c131f6a75 100644
--- a/visualizer.py
+++ b/visualizer.py
@@ -5,10 +5,6 @@ import math
 from types import SimpleNamespace
 from urllib.request import urlopen
 
-# Activate the virtual env to get access to non-standard packages.
-activator = 'venv/bin/activate_this.py'
-exec(open(activator).read(), {'__file__': activator})
-
 import asccol
 from dataclasses import make_dataclass
 from flask import abort, Flask, g, jsonify, render_template, request, Response