diff --git a/Core/CoreParameter.h b/Core/CoreParameter.h
index a39385f5b5..bd9b219e62 100644
--- a/Core/CoreParameter.h
+++ b/Core/CoreParameter.h
@@ -49,8 +49,15 @@ struct CoreParameter
 	bool printfEmuLog;  // writes "emulator:" logging to stdout
 	bool headLess;   // Try to avoid messageboxes etc
 
+	// Internal PSP resolution
 	int renderWidth;
 	int renderHeight;
+
+	// Virtual (dpi-adjusted) output resolution
 	int outputWidth;
 	int outputHeight;
+
+	// Actual pixel output resolution (for use by glViewport and the like)
+	int pixelWidth;
+	int pixelHeight;
 };
diff --git a/GPU/GLES/DisplayListInterpreter.cpp b/GPU/GLES/DisplayListInterpreter.cpp
index adcb193fd2..bb5ac7cf61 100644
--- a/GPU/GLES/DisplayListInterpreter.cpp
+++ b/GPU/GLES/DisplayListInterpreter.cpp
@@ -82,7 +82,7 @@ void GLES_GPU::InitClear()
 		//	glClearColor(1,0,1,1);
 		glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
 	}
-	glViewport(0, 0, renderWidth_, renderHeight_);
+	glViewport(0, 0, PSP_CoreParameter().pixelWidth, PSP_CoreParameter().pixelHeight);
 }
 
 void GLES_GPU::BeginFrame()
@@ -115,7 +115,7 @@ void GLES_GPU::CopyDisplayToOutput()
 	VirtualFramebuffer *vfb = GetDisplayFBO();
 	fbo_unbind();
 
-	glViewport(0, 0, PSP_CoreParameter().outputWidth, PSP_CoreParameter().outputHeight);
+	glViewport(0, 0, PSP_CoreParameter().pixelWidth, PSP_CoreParameter().pixelHeight);
 
 	currentRenderVfb_ = 0;
 
diff --git a/Windows/EmuThread.cpp b/Windows/EmuThread.cpp
index 5187227481..da27fd6804 100644
--- a/Windows/EmuThread.cpp
+++ b/Windows/EmuThread.cpp
@@ -60,18 +60,20 @@ DWORD TheThread(LPVOID x)
 
 	INFO_LOG(BOOT, "Starting up hardware.");
 
-  CoreParameter coreParameter;
-  coreParameter.fileToStart = fileToStart;
-  coreParameter.enableSound = true;
-  coreParameter.gpuCore = GPU_GLES;
-  coreParameter.cpuCore = g_Config.bJIT ? CPU_JIT : CPU_INTERPRETER;
-  coreParameter.enableDebugging = true;
-  coreParameter.printfEmuLog = false;
-  coreParameter.headLess = false;
+	CoreParameter coreParameter;
+	coreParameter.fileToStart = fileToStart;
+	coreParameter.enableSound = true;
+	coreParameter.gpuCore = GPU_GLES;
+	coreParameter.cpuCore = g_Config.bJIT ? CPU_JIT : CPU_INTERPRETER;
+	coreParameter.enableDebugging = true;
+	coreParameter.printfEmuLog = false;
+	coreParameter.headLess = false;
 	coreParameter.renderWidth = 480 * g_Config.iWindowZoom;
 	coreParameter.renderHeight = 272 * g_Config.iWindowZoom;
 	coreParameter.outputWidth = 480 * g_Config.iWindowZoom;
 	coreParameter.outputHeight = 272 * g_Config.iWindowZoom;
+	coreParameter.pixelWidth = 480 * g_Config.iWindowZoom;
+	coreParameter.pixelHeight = 272 * g_Config.iWindowZoom;
 
 	std::string error_string;
 	if (!PSP_Init(coreParameter, &error_string))
diff --git a/android/jni/EmuScreen.cpp b/android/jni/EmuScreen.cpp
index a2c07a60b9..7b11d3c9ed 100644
--- a/android/jni/EmuScreen.cpp
+++ b/android/jni/EmuScreen.cpp
@@ -65,6 +65,8 @@ EmuScreen::EmuScreen(const std::string &filename) : invalid_(true)
 	coreParam.renderHeight = 272;
 	coreParam.outputWidth = dp_xres;
 	coreParam.outputHeight = dp_yres;
+	coreParam.pixelWidth = pixel_xres;
+	coreParam.pixelHeight = pixel_yres;
 
 	std::string error_string;
 	if (PSP_Init(coreParam, &error_string)) {
@@ -176,7 +178,7 @@ void EmuScreen::render()
 
 	uiTexture->Bind(0);
 
-	glViewport(0, 0, dp_xres, dp_yres);
+	glViewport(0, 0, pixel_xres, pixel_yres);
 
 	ui_draw2d.Begin(DBMODE_NORMAL);