diff --git a/imgui-sys/src/lib.rs b/imgui-sys/src/lib.rs
index ba670c9..8173361 100644
--- a/imgui-sys/src/lib.rs
+++ b/imgui-sys/src/lib.rs
@@ -151,6 +151,7 @@ pub enum ImGuiStyleVar {
     Alpha,
     WindowPadding,
     WindowRounding,
+    WindowBorderSize,
     WindowMinSize,
     ChildRounding,
     ChildBorderSize,
@@ -165,7 +166,7 @@ pub enum ImGuiStyleVar {
     GrabMinSize,
     ButtonTextAlign,
 }
-pub const ImGuiStyleVar_COUNT: usize = 16;
+pub const ImGuiStyleVar_COUNT: usize = 17;
 
 impl ImGuiStyleVar {
     #[deprecated(since = "0.0.19", note = "please use ChildRounding instead")]
diff --git a/src/lib.rs b/src/lib.rs
index 2c310c7..0c99b31 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1202,6 +1202,7 @@ impl<'ui> Ui<'ui> {
             Alpha(v) => unsafe { igPushStyleVar(ImGuiStyleVar::Alpha, v) },
             WindowPadding(v) => unsafe { igPushStyleVarVec(ImGuiStyleVar::WindowPadding, v) },
             WindowRounding(v) => unsafe { igPushStyleVar(ImGuiStyleVar::WindowRounding, v) },
+            WindowBorderSize(v) => unsafe { igPushStyleVar(ImGuiStyleVar::WindowBorderSize, v) },
             WindowMinSize(v) => unsafe { igPushStyleVarVec(ImGuiStyleVar::WindowMinSize, v) },
             ChildRounding(v) => unsafe {
                 igPushStyleVar(ImGuiStyleVar::ChildRounding, v)
diff --git a/src/style.rs b/src/style.rs
index 5859be8..5e3039b 100644
--- a/src/style.rs
+++ b/src/style.rs
@@ -5,6 +5,7 @@ pub enum StyleVar {
     Alpha(f32),
     WindowPadding(ImVec2),
     WindowRounding(f32),
+    WindowBorderSize(f32),
     WindowMinSize(ImVec2),
     ChildRounding(f32),
     ChildBorderSize(f32),
diff --git a/src/window.rs b/src/window.rs
index b1330ca..7f6427e 100644
--- a/src/window.rs
+++ b/src/window.rs
@@ -161,7 +161,7 @@ impl<'ui, 'p> Window<'ui, 'p> {
                 sys::igSetNextWindowSize(self.size.into(), self.size_cond);
             }
             if self.border {
-                sys::igPushStyleVar(ImGuiStyleVar::FrameBorderSize, 1.0);
+                sys::igPushStyleVar(ImGuiStyleVar::WindowBorderSize, 1.0);
             }
             sys::igBegin(
                 self.name.as_ptr(),