diff --git a/GPU/Directx9/FramebufferDX9.cpp b/GPU/Directx9/FramebufferDX9.cpp
index 3b97be8f2b..63ec3533f9 100644
--- a/GPU/Directx9/FramebufferDX9.cpp
+++ b/GPU/Directx9/FramebufferDX9.cpp
@@ -43,8 +43,6 @@
 #include <xmmintrin.h>
 #endif
 
-void ShowScreenResolution();
-
 namespace DX9 {
 	static void ConvertFromRGBA8888(u8 *dst, u8 *src, u32 dstStride, u32 srcStride, u32 width, u32 height, GEBufferFormat format);
 
diff --git a/GPU/GLES/Framebuffer.cpp b/GPU/GLES/Framebuffer.cpp
index 3e1ac8e02b..b7d10993c0 100644
--- a/GPU/GLES/Framebuffer.cpp
+++ b/GPU/GLES/Framebuffer.cpp
@@ -1783,10 +1783,6 @@ void FramebufferManager::PackDepthbuffer(VirtualFramebuffer *vfb, int x, int y,
 	fbo_unbind_read();
 }
 
-#ifdef _WIN32
-void ShowScreenResolution();
-#endif
-
 void FramebufferManager::EndFrame() {
 	if (resized_) {
 		// TODO: Only do this if the new size actually changed the renderwidth/height.
diff --git a/GPU/Vulkan/FramebufferVulkan.cpp b/GPU/Vulkan/FramebufferVulkan.cpp
index 3926644394..64ab3865ad 100644
--- a/GPU/Vulkan/FramebufferVulkan.cpp
+++ b/GPU/Vulkan/FramebufferVulkan.cpp
@@ -1420,10 +1420,6 @@ void FramebufferManagerVulkan::PackFramebufferSync_(VirtualFramebuffer *vfb, int
 
 }
 
-#ifdef _WIN32
-void ShowScreenResolution();
-#endif
-
 VkCommandBuffer FramebufferManagerVulkan::AllocFrameCommandBuffer() {
 	FrameData &frame = frameData_[curFrame_];
 	int num = frame.numCommandBuffers_;