diff --git a/imgui-sys/src/lib.rs b/imgui-sys/src/lib.rs
index 72dc86995..bc5b96ba2 100644
--- a/imgui-sys/src/lib.rs
+++ b/imgui-sys/src/lib.rs
@@ -1851,6 +1851,10 @@ extern "C" {
     pub fn igSetCurrentContext(ctx: *mut ImGuiContext);
 }
 
+extern "C" {
+    pub fn ImFontConfig_DefaultConstructor(config: *mut ImFontConfig);
+}
+
 // ImGuiIO
 extern "C" {
     pub fn ImGuiIO_AddInputCharacter(c: c_ushort);