diff --git a/devscripts/youtube_genalgo.py b/devscripts/youtube_genalgo.py
index 917e8f79d2..b06416e936 100644
--- a/devscripts/youtube_genalgo.py
+++ b/devscripts/youtube_genalgo.py
@@ -20,9 +20,9 @@
     # 87
     ("qwertyuioplkjhgfdsazxcvbnm1234567890QWERTYUIOPLKJHGFDSAZXCVBNM!@#$^&*()_-+={[]}|:;?/>.<",
      "uioplkjhgfdsazxcvbnm1t34567890QWE2TYUIOPLKJHGFDSAZXCVeNM!@#$^&*()_-+={[]}|:;?/>.<"),
-    # 86 - vflh9ybst 2013/08/23
+    # 86 - vflg0g8PQ 2013/08/29
     ("qwertyuioplkjhgfdsazxcvbnm1234567890QWERTYUIOPLKJHGFDSAZXCVBNM!@#$%^&*()_-+={[|};?/>.<",
-     "yuioplkjhgfdsazxcvbnm1234567890QWERrYUIOPLKqHGFDSAZXCVBNM!@#$%^&*()_-+={[|};?/>.<"),
+     ">/?;}|[{=+-_)(*&^%$#@!MNBVCXZASDFGHJKLPOIUYTREWq0987654321mnbvcxzasdfghjklpoiuytr"),
     # 85
     ("qwertyuioplkjhgfdsazxcvbnm1234567890QWERTYUIOPLKJHGFDSAZXCVBNM!@#$%^&*()_-+={[};?/>.<",
      ".>/?;}[{=+-_)(*&^%$#@!MNBVCXZASDFGHJKLPOIUYTREWQ0q876543r1mnbvcx9asdfghjklpoiuyt2"),
diff --git a/youtube_dl/extractor/youtube.py b/youtube_dl/extractor/youtube.py
index 4038af2560..3a07df0272 100644
--- a/youtube_dl/extractor/youtube.py
+++ b/youtube_dl/extractor/youtube.py
@@ -423,7 +423,7 @@ def _decrypt_signature(self, s):
         elif len(s) == 87:
             return s[6:27] + s[4] + s[28:39] + s[27] + s[40:59] + s[2] + s[60:]
         elif len(s) == 86:
-            return s[5:40] + s[3] + s[41:48] + s[0] + s[49:86]
+            return s[83:36:-1] + s[0] + s[35:2:-1]
         elif len(s) == 85:
             return s[83:34:-1] + s[0] + s[33:27:-1] + s[3] + s[26:19:-1] + s[34] + s[18:3:-1] + s[27]
         elif len(s) == 84: