diff --git a/lib/generate-privkey.js b/lib/generate-privkey.js
index afeb484..1d580d6 100644
--- a/lib/generate-privkey.js
+++ b/lib/generate-privkey.js
@@ -23,6 +23,22 @@ module.exports = function (bitlen, exp) {
         console.warn("[WARN] rsa-compat: Your version of node does not have crypto.generateKeyPair()");
         console.warn("[WARN] rsa-compat: Please update to node >= v10.12 or 'npm install ursa'");
         console.warn("[WARN] rsa-compat: Using node-forge as a fallback, but it may be unacceptably slow.");
+        if (/arm|mips/i.test(require('os').arch)) {
+          console.warn("================================================================");
+          console.warn("                         WARNING");
+          console.warn("================================================================");
+          console.warn("");
+          console.warn("WARNING: You are generating an RSA key using pure JavaScript on");
+          console.warn("         a VERY SLOW cpu. This could take DOZENS of minutes!");
+          console.warn("");
+          console.warn("         We recommend installing node >= v10.12, or 'gcc' and 'ursa'");
+          console.warn("");
+          console.warn("EXAMPLE:");
+          console.warn("");
+          console.warn("        sudo apt-get install build-essential && npm install ursa");
+          console.warn("");
+          console.warn("================================================================");
+        }
       }
       try {
         return require('./generate-privkey-forge')(bitlen, exp);