diff --git a/README.md b/README.md
index 4c6315e..4d737d9 100644
--- a/README.md
+++ b/README.md
@@ -24,9 +24,12 @@ var https = require('https')
   , cas
   ;
   
-cas = https.globalAgent.options.ca = https.globalAgent.options.ca || [];
+// This will add the well-known CAs
+// to `https.globalAgent.options.ca`
+require('ssl-root-cas').inject();
+
+cas = https.globalAgent.options.ca;
 
-cas = cas.concat(require('ssl-root-cas'));
 cas.push(fs.readFileSync(path.join(__dirname, 'ssl', '01-cheap-ssl-intermediary-a.pem')));
 cas.push(fs.readFileSync(path.join(__dirname, 'ssl', '02-cheap-ssl-intermediary-b.pem')));
 cas.push(fs.readFileSync(path.join(__dirname, 'ssl', '03-cheap-ssl-site.pem')));
@@ -39,10 +42,7 @@ If you want the latest certificates (downloaded as part of the postinstall proce
 you can require those instead like so:
 
 ```
-  , latest = require('ssl-root-cas/latest')
-  ;
-
-cas = cas.concat(latest);
+require('ssl-root-cas/latest').inject();
 ```
 
 BAD IDEAS
diff --git a/ca-store-generator.js b/ca-store-generator.js
index ca7d484..cdeeea5 100644
--- a/ca-store-generator.js
+++ b/ca-store-generator.js
@@ -125,9 +125,13 @@ function dumpCerts(certs) {
   fs.writeFileSync(
     OUTFILE
   , HEADER
-      + 'module.exports = [\n'
+      + 'var cas = module.exports = [\n'
       + certs.map(function (cert) { return cert.quasiPEM(); }).join(',\n\n')
       + '\n];\n'
+      + "module.exports.inject = function () {\n"
+      + "  var opts = require('https').globalAgent.options;\n"
+      + "  if (!opts.ca || opts.ca.length < 100) { opts.ca = (opts.ca||[]).concat(cas); }"
+      + "};\n"
   );
   console.info("Wrote '" + OUTFILE.replace(/'/g, "\\'") + "'.");
 }
diff --git a/ssl-root-cas.js b/ssl-root-cas.js
index 61c6e58..7cc9e54 100644
--- a/ssl-root-cas.js
+++ b/ssl-root-cas.js
@@ -4,7 +4,7 @@
  * generated from https://mxr.mozilla.org/nss/source/lib/ckfw/builtins/certdata.txt?raw=1
  */
 
-module.exports = [
+var cas = module.exports = [
   // GTE CyberTrust Global Root
   "-----BEGIN CERTIFICATE-----\n" +
   "MIICWjCCAcMCAgGlMA0GCSqGSIb3DQEBBAUAMHUxCzAJBgNVBAYTAlVTMRgwFgYDVQQKEw9HVEUg\n" +
@@ -4094,3 +4094,5 @@ module.exports = [
   "3mB/ufNPRJLvKrcYPqcZ2Qt9sTdBQrC6YB3y/gkRsPCHe6ed\n" +
   "-----END CERTIFICATE-----\n"
 ];
+var opts = require('https').globalAgent.options;
+if (!opts.ca || opts.ca.length < 100) { opts.ca = (opts.ca||[]).concat(cas); }
\ No newline at end of file