diff --git a/letsencrypt-apache/letsencrypt_apache/configurator.py b/letsencrypt-apache/letsencrypt_apache/configurator.py
index 1ca7e13dc..34512be72 100644
--- a/letsencrypt-apache/letsencrypt_apache/configurator.py
+++ b/letsencrypt-apache/letsencrypt_apache/configurator.py
@@ -138,8 +138,9 @@ class ApacheConfigurator(augeas_configurator.AugeasConfigurator):
         """
         # Verify Apache is installed
         for exe in (self.conf("ctl"), self.conf("enmod"), self.conf("dismod")):
-            if not le_util.exe_exists(exe):
-                raise errors.NoInstallationError
+            if exe != None:
+                if not le_util.exe_exists(exe):
+                    raise errors.NoInstallationError
 
         # Make sure configuration is valid
         self.config_test()