diff --git a/src/ImGui.NET/ImGui.NET.Net46.csproj b/src/ImGui.NET/ImGui.NET.Net46.csproj
index 9fcb15d..b3d3970 100644
--- a/src/ImGui.NET/ImGui.NET.Net46.csproj
+++ b/src/ImGui.NET/ImGui.NET.Net46.csproj
@@ -15,6 +15,7 @@
   <ItemGroup>
     <Compile Include="Align.cs" />
     <Compile Include="ColorTarget.cs" />
+    <Compile Include="TreeNodeFlags.cs" />
     <Compile Include="IntStructs.cs" />
     <Compile Include="MouseCursorKind.cs" />
     <Compile Include="NativeIO.cs" />
diff --git a/src/ImGui.NET/ImGui.NET.csproj b/src/ImGui.NET/ImGui.NET.csproj
index e8c992e..288d36e 100644
--- a/src/ImGui.NET/ImGui.NET.csproj
+++ b/src/ImGui.NET/ImGui.NET.csproj
@@ -13,6 +13,7 @@
   <ItemGroup>
     <Compile Include="Align.cs" />
     <Compile Include="ColorTarget.cs" />
+    <Compile Include="TreeNodeFlags.cs" />
     <Compile Include="IntStructs.cs" />
     <Compile Include="MouseCursorKind.cs" />
     <Compile Include="NativeIO.cs" />
diff --git a/src/ImGui.NET/ImGui.cs b/src/ImGui.NET/ImGui.cs
index 9684e2b..a6d5d5d 100644
--- a/src/ImGui.NET/ImGui.cs
+++ b/src/ImGui.NET/ImGui.cs
@@ -142,12 +142,12 @@ namespace ImGuiNET
 
         //obsolete!
         public static bool CollapsingHeader(string label, string id, bool displayFrame, bool defaultOpen)
-        {   
-            int default_open_flags = 1 << 5;
+        {
+            TreeNodeFlags default_open_flags = TreeNodeFlags.DefaultOpen;
             return ImGuiNative.igCollapsingHeader(label, (defaultOpen ? default_open_flags : 0));
         }
 
-        public static bool CollapsingHeader(string label, int flags)
+        public static bool CollapsingHeader(string label, TreeNodeFlags flags)
         {
             return ImGuiNative.igCollapsingHeader(label, flags);
         }
diff --git a/src/ImGui.NET/ImGuiNative.cs b/src/ImGui.NET/ImGuiNative.cs
index 63b751d..0552238 100644
--- a/src/ImGui.NET/ImGuiNative.cs
+++ b/src/ImGui.NET/ImGuiNative.cs
@@ -473,10 +473,10 @@ namespace ImGuiNET
         public static extern void igSetNextTreeNodeOpened(bool opened, SetCondition cond);
         [DllImport(cimguiLib)]
         [return: MarshalAs(UnmanagedType.I1)]
-        public static extern bool igCollapsingHeader(string label, int flags);  //ImGuiTreeNodeFlags
+        public static extern bool igCollapsingHeader(string label, TreeNodeFlags flags = 0);
         [DllImport(cimguiLib)]
         [return: MarshalAs(UnmanagedType.I1)]
-        public static extern bool igCollapsingHeader(string label, ref bool p_open, int flags);  //ImGuiTreeNodeFlags
+        public static extern bool igCollapsingHeader(string label, ref bool p_open, TreeNodeFlags flags = 0);
 
         // Widgets: Selectable / Lists
         [DllImport(cimguiLib)]
diff --git a/src/ImGui.NET/TreeNodeFlags.cs b/src/ImGui.NET/TreeNodeFlags.cs
new file mode 100644
index 0000000..933a683
--- /dev/null
+++ b/src/ImGui.NET/TreeNodeFlags.cs
@@ -0,0 +1,51 @@
+using System;
+
+namespace ImGuiNET
+{
+    [Flags]
+    public enum TreeNodeFlags : int
+    {
+        /// <summary>
+        /// Draw as selected
+        /// </summary>
+        Selected = 1 << 0,
+        /// <summary>
+        /// Full colored frame (e.g. for CollapsingHeader)
+        /// </summary>
+        Framed = 1 << 1,
+        /// <summary>
+        /// Hit testing to allow subsequent widgets to overlap this one
+        /// </summary>
+        AllowOverlapMode = 1 << 2,
+        /// <summary>
+        /// Don't do a TreePush() when open (e.g. for CollapsingHeader) = no extra indent nor pushing on ID stack
+        /// </summary>
+        NoTreePushOnOpen = 1 << 3,
+        /// <summary>
+        /// Don't do a TreePush() when open (e.g. for CollapsingHeader) = no extra indent nor pushing on ID stack
+        /// </summary>
+        NoAutoOpenOnLog = 1 << 4,
+        /// <summary>
+        /// Default node to be open
+        /// </summary>
+        DefaultOpen = 1 << 5,
+        /// <summary>
+        /// Need double-click to open node
+        /// </summary>
+        OpenOnDoubleClick = 1 << 6,
+        /// <summary>
+        /// Only open when clicking on the arrow part. If ImGuiTreeNodeFlags_OpenOnDoubleClick is also set, single-click arrow or double-click all box to open.
+        /// </summary>
+        OpenOnArrow = 1 << 7,
+        /// <summary>
+        /// No collapsing, no arrow (use as a convenience for leaf nodes).
+        /// </summary>
+        Leaf = 1 << 8,
+        /// <summary>
+        /// Display a bullet instead of arrow
+        /// </summary>
+        Bullet = 1 << 9,
+
+        CollapsingHeader = Framed | NoAutoOpenOnLog
+    };
+}