diff --git a/examples/imgui_impl_sdl2.cpp b/examples/imgui_impl_sdl2.cpp
index b1c757db..7cd47f63 100644
--- a/examples/imgui_impl_sdl2.cpp
+++ b/examples/imgui_impl_sdl2.cpp
@@ -27,7 +27,6 @@
 
 #include "imgui.h"
 #include "imgui_impl_sdl2.h"
-
 #include "imgui_internal.h" // FIXME-PLATFORM
 
 // SDL
@@ -149,11 +148,14 @@ bool    ImGui_ImplSDL2_Init(SDL_Window* window, void* sdl_gl_context)
     // Our mouse update function expect PlatformHandle to be filled for the main viewport
     ImGuiViewport* main_viewport = ImGui::GetMainViewport();
     main_viewport->PlatformHandle = (void*)window;
+
+    // We need SDL_CaptureMouse(), SDL_GetGlobalMouseState() from SDL 2.0.4+ to support multiple viewports.
+    // We left the call to ImGui_ImplSDL2_InitPlatformInterface() outside of #ifdef to avoid unused-function warnings.
 #if SDL_VERSION_ATLEAST(2,0,4)
     io.ConfigFlags |= ImGuiConfigFlags_PlatformHasViewports;
-    if (io.ConfigFlags & ImGuiConfigFlags_EnableViewports)
-        ImGui_ImplSDL2_InitPlatformInterface(window, sdl_gl_context);
 #endif
+    if ((io.ConfigFlags & ImGuiConfigFlags_EnableViewports) && (io.ConfigFlags & ImGuiConfigFlags_PlatformHasViewports))
+        ImGui_ImplSDL2_InitPlatformInterface(window, sdl_gl_context);
 
     return true;
 }
@@ -252,9 +254,7 @@ void ImGui_ImplSDL2_NewFrame(SDL_Window* window)
 // Platform Windows
 // --------------------------------------------------------------------------------------------------------
 
-#include "imgui_internal.h"
-
-#define SDL_HAS_WINDOW_OPACITY  SDL_VERSION_ATLEAST(2,0,5)
+#define SDL_HAS_WINDOW_OPACITY      SDL_VERSION_ATLEAST(2,0,5)
 
 struct ImGuiPlatformDataSDL2
 {
@@ -331,8 +331,8 @@ static void ImGui_ImplSDL2_ShowWindow(ImGuiViewport* viewport)
             return;
         }
 }
-
 #endif
+
     SDL_ShowWindow(data->Window);
 }
 
diff --git a/imgui.cpp b/imgui.cpp
index eaf8d7bd..bfc85340 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -5194,12 +5194,6 @@ ImVec2 ImGui::GetItemRectSize()
     return window->DC.LastItemRect.GetSize();
 }
 
-static ImRect GetViewportRect()
-{
-    ImGuiContext& g = *GImGui;
-    return ImRect(0.0f, 0.0f, g.IO.DisplaySize.x, g.IO.DisplaySize.y);
-}
-
 // Not exposed publicly as BeginTooltip() because bool parameters are evil. Let's see if other needs arise first.
 void ImGui::BeginTooltipEx(ImGuiWindowFlags extra_flags, bool override_previous_tooltip)
 {