diff --git a/HISTORY.rst b/HISTORY.rst
index f78ece9f..f244ded7 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -4,7 +4,7 @@ Release Notes
 PlatformIO 3.0
 --------------
 
-3.6.6 (2019-??-??)
+3.6.6 (2019-03-29)
 ~~~~~~~~~~~~~~~~~~
 
 * Project Generator: fixed a warning "Property !!! WARNING !!! is not allowed" for VSCode
diff --git a/docs b/docs
index 7349afe0..3a6c69a1 160000
--- a/docs
+++ b/docs
@@ -1 +1 @@
-Subproject commit 7349afe05572deec8cdf28378d8339519af9615d
+Subproject commit 3a6c69a1ae227479321de75184aa8678104fc37f
diff --git a/platformio/__init__.py b/platformio/__init__.py
index 93a24702..6b913ff6 100644
--- a/platformio/__init__.py
+++ b/platformio/__init__.py
@@ -14,7 +14,7 @@
 
 import sys
 
-VERSION = (3, 6, "6a1")
+VERSION = (3, 6, 6)
 __version__ = ".".join([str(s) for s in VERSION])
 
 __title__ = "platformio"