diff --git a/packages/gitbook-plugin-theme-default/less/Body.less b/packages/gitbook-plugin-theme-default/less/Body.less
new file mode 100644
index 000000000..7524a247c
--- /dev/null
+++ b/packages/gitbook-plugin-theme-default/less/Body.less
@@ -0,0 +1,5 @@
+.Body {
+    overflow: auto;
+    width: 100%;
+    height: 100%;
+}
diff --git a/packages/gitbook-plugin-theme-default/less/main.less b/packages/gitbook-plugin-theme-default/less/main.less
index 9858a2fd0..cb5d07d32 100644
--- a/packages/gitbook-plugin-theme-default/less/main.less
+++ b/packages/gitbook-plugin-theme-default/less/main.less
@@ -12,6 +12,7 @@
 @import "Page.less";
 @import "Toolbar.less";
 @import "Search.less";
+@import "Body.less";
 
 * {
     .box-sizing(border-box);