diff --git a/src/main/ua-parser.js b/src/main/ua-parser.js
index a5e8d63..a449ada 100755
--- a/src/main/ua-parser.js
+++ b/src/main/ua-parser.js
@@ -965,7 +965,7 @@
             /(mageia|vectorlinux)[; ]/i,                                        // Mageia/VectorLinux
             /([kxln]?ubuntu|debian|suse|opensuse|gentoo|arch(?= linux)|slackware|fedora|mandriva|centos|pclinuxos|red ?hat|zenwalk|linpus|raspbian|plan 9|minix|risc os|contiki|deepin|manjaro|elementary os|sabayon|linspire)(?: gnu\/linux)?(?: enterprise)?(?:[- ]linux)?(?:-gnu)?[-\/ ]?(?!chrom|package)([-\w\.]*)/i,
                                                                                 // Ubuntu/Debian/SUSE/Gentoo/Arch/Slackware/Fedora/Mandriva/CentOS/PCLinuxOS/RedHat/Zenwalk/Linpus/Raspbian/Plan9/Minix/RISCOS/Contiki/Deepin/Manjaro/elementary/Sabayon/Linspire
-            /(hurd|linux) ?([\w\.]*)/i,                                         // Hurd/Linux
+            /(hurd|linux)(?: arm\w*| x86\w*| ?)([\w\.]*)/i,                     // Hurd/Linux
             /(gnu) ?([\w\.]*)/i,                                                // GNU
             /\b([-frentopcghs]{0,5}bsd|dragonfly)[\/ ]?(?!amd|[ix346]{1,2}86)([\w\.]*)/i, // FreeBSD/NetBSD/OpenBSD/PC-BSD/GhostBSD/DragonFly
             /(haiku) (\w+)/i                                                    // Haiku
diff --git a/test/data/ua/os/linux.json b/test/data/ua/os/linux.json
index ad86c4e..af78593 100644
--- a/test/data/ua/os/linux.json
+++ b/test/data/ua/os/linux.json
@@ -5,7 +5,16 @@
         "expect"  :
         {
             "name"    : "Linux",
-            "version" : "x86_64"
+            "version" : "undefined"
+        }
+    },
+    {
+        "desc"    : "Linux",
+        "ua"      : "Mozilla/5.0 (X11; U; Linux armv61; en-US; rv:1.9.1b2pre) Gecko/20081015 Fennec/1.0a1",
+        "expect"  :
+        {
+            "name"    : "Linux",
+            "version" : "undefined"
         }
     }
 ]
\ No newline at end of file
diff --git a/test/unit/ua-ch.js b/test/unit/ua-ch.js
index 1342a35..71bfdea 100644
--- a/test/unit/ua-ch.js
+++ b/test/unit/ua-ch.js
@@ -68,7 +68,7 @@ describe('Map UA-CH headers', () => {
         assert.strictEqual(uap.engine.name, 'Blink');
         assert.strictEqual(uap.engine.version, '110.0.0.0');
         assert.strictEqual(uap.os.name, "Linux");
-        assert.strictEqual(uap.os.version, "x86_64");
+        assert.strictEqual(uap.os.version, undefined);
     });
 
     it('Fallback to user-agent header when using `withClientHints()` but found no client hints-related headers',  () => {  
@@ -90,7 +90,7 @@ describe('Map UA-CH headers', () => {
         assert.strictEqual(uap.engine.name, 'Blink');
         assert.strictEqual(uap.engine.version, '110.0.0.0');
         assert.strictEqual(uap.os.name, "Linux");
-        assert.strictEqual(uap.os.version, "x86_64");
+        assert.strictEqual(uap.os.version, undefined);
     });
 
     it('Can detect Apple silicon from client hints data', () => {