diff --git a/lib/extensions.js b/lib/extensions.js
index fcfffdc19..2e9020229 100644
--- a/lib/extensions.js
+++ b/lib/extensions.js
@@ -43,6 +43,8 @@ function getHumanArchitecture(arch) {
     case 'ia32': return '32-bit';
     case 'x86': return '32-bit';
     case 'x64': return '64-bit';
+    case 'ppc64': return '64-bit';
+    case 's390x': return '64-bit';
     default: return false;
   }
 }
diff --git a/test/errors.js b/test/errors.js
index 537ebb6df..fb9ba173d 100644
--- a/test/errors.js
+++ b/test/errors.js
@@ -16,7 +16,8 @@ describe('binary errors', function() {
   function getCurrentArchitecture() {
     if (process.arch === 'x86' || process.arch === 'ia32') {
       return '32-bit';
-    } else if (process.arch === 'x64') {
+    } else if (process.arch === 'x64' || process.arch === 'ppc64' ||
+               process.arch === 's390x') {
       return '64-bit';
     }
     return '';