diff --git a/hello_imgui_cmake/hello_imgui_build_lib.cmake b/hello_imgui_cmake/hello_imgui_build_lib.cmake
index 7d1e7685..56fe09ae 100644
--- a/hello_imgui_cmake/hello_imgui_build_lib.cmake
+++ b/hello_imgui_cmake/hello_imgui_build_lib.cmake
@@ -736,6 +736,11 @@ function(him_has_opengl3 target)
 
     if (IOS OR EMSCRIPTEN)
         set(HELLOIMGUI_USE_GLAD OFF CACHE INTERNAL "" FORCE)
+        target_compile_definitions(${target}
+            PUBLIC
+            IMGUI_IMPL_OPENGL_ES3
+            HELLOIMGUI_USE_GLES3
+        )
     else()
         set(HELLOIMGUI_USE_GLAD ON CACHE INTERNAL "" FORCE)
     endif()