diff --git a/imgui.cpp b/imgui.cpp
index 8eb17280..3a1aaba3 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -2300,6 +2300,7 @@ ImDrawListSharedData* ImGui::GetDrawListSharedData()
 
 void ImGui::NewFrame()
 {
+    IM_ASSERT(GImGui != NULL && "No current context. Did you call ImGui::CreateContext() or ImGui::SetCurrentContext()?");
     ImGuiContext& g = *GImGui;
 
     // Check user data