diff --git a/_config.yml b/_config.yml
index 0dc9c63d69..1610f84a57 100644
--- a/_config.yml
+++ b/_config.yml
@@ -319,6 +319,11 @@ cheers_enabled: true
 # Leave it empty for the default 75% (suggest not less than 1000px)
 #max_content_width: 1000px
 
+# Manual define the sidebar width
+# !!Only available for Gemini Scheme currently
+# Leave it empty for the default 240
+sidebar_width:
+
 # ---------------------------------------------------------------
 # Font Settings
 # - Find fonts on Google Fonts (https://www.google.com/fonts)
diff --git a/source/css/_schemes/Pisces/_layout.styl b/source/css/_schemes/Pisces/_layout.styl
index f7e5e0de9e..a3a2b5223d 100644
--- a/source/css/_schemes/Pisces/_layout.styl
+++ b/source/css/_schemes/Pisces/_layout.styl
@@ -16,13 +16,13 @@
   top: 0;
   overflow: hidden;
   padding: 0;
-  width: 240px;
+  width: $sidebar-desktop;
   background: white;
   box-shadow: $box-shadow-inner;
   border-radius: $border-radius-inner;
 
   +desktop-large() {
-    .container & { width: 240px; }
+    .container & { width: $sidebar-desktop; }
   }
   +tablet() {
     position: relative;
diff --git a/source/css/_schemes/Pisces/_sidebar.styl b/source/css/_schemes/Pisces/_sidebar.styl
index 769cec6556..9ced486498 100644
--- a/source/css/_schemes/Pisces/_sidebar.styl
+++ b/source/css/_schemes/Pisces/_sidebar.styl
@@ -14,7 +14,7 @@
 .sidebar-inner {
 //padding: 20px 10px 0;
   box-sizing: border-box;
-  width: 240px;
+  width: $sidebar-desktop;
   color: $text-color;
   background: white;
   box-shadow: $box-shadow;
diff --git a/source/css/_variables/Gemini.styl b/source/css/_variables/Gemini.styl
index 4d6e7e01a3..04e14ef756 100644
--- a/source/css/_variables/Gemini.styl
+++ b/source/css/_variables/Gemini.styl
@@ -7,8 +7,9 @@
 // --------------------------------------------------
 $body-bg-color                    = #eee
 $main-desktop                     = 75%
-$sidebar-desktop                  = 240px
-$content-desktop                  = calc(100% - 252px)
+$sidebar-width                    = hexo-config('sidebar_width') is a 'unit' ? hexo-config('sidebar_width') : 240
+$sidebar-desktop                  = unit($sidebar-width, 'px')
+$content-desktop                  = 'calc(100% - %s)' % unit($sidebar-width + 12, 'px')
 
 // Borders.
 // --------------------------------------------------