diff --git a/GPU/Common/FramebufferCommon.cpp b/GPU/Common/FramebufferCommon.cpp
index 5b4f494b25dd..344919f97666 100644
--- a/GPU/Common/FramebufferCommon.cpp
+++ b/GPU/Common/FramebufferCommon.cpp
@@ -59,16 +59,16 @@ void CenterDisplayOutputRect(float *x, float *y, float *w, float *h, float origW
 				float smallDisplayW = origW * customZoom;
 				float smallDisplayH = origH * customZoom;
 				if (!rotated) {
-					*x = ((frameW - smallDisplayW) / 2.0f) + offsetX;
-					*y = ((frameH - smallDisplayH) / 2.0f) + offsetY;
-					*w = smallDisplayW;
-					*h = smallDisplayH;
+					*x = floorf(((frameW - smallDisplayW) / 2.0f) + offsetX);
+					*y = floorf(((frameH - smallDisplayH) / 2.0f) + offsetY);
+					*w = floorf(smallDisplayW);
+					*h = floorf(smallDisplayH);
 					return;
 				} else {
-					*x = ((frameW - smallDisplayH) / 2.0f) + offsetX;
-					*y = ((frameH - smallDisplayW) / 2.0f) + offsetY;
-					*w = smallDisplayH;
-					*h = smallDisplayW;
+					*x = floorf(((frameW - smallDisplayH) / 2.0f) + offsetX);
+					*y = floorf(((frameH - smallDisplayW) / 2.0f) + offsetY);
+					*w = floorf(smallDisplayH);
+					*h = floorf(smallDisplayW);
 					return;
 				}
 			} else {
@@ -76,9 +76,9 @@ void CenterDisplayOutputRect(float *x, float *y, float *w, float *h, float origW
 				float resCommonWidescreen = pixelCrop - floor(pixelCrop);
 				if (!rotated && resCommonWidescreen == 0.0f) {
 					*x = 0;
-					*y = -pixelCrop;
-					*w = frameW;
-					*h = pixelCrop * 272.0f;
+					*y = floorf(-pixelCrop);
+					*w = floorf(frameW);
+					*h = floorf(pixelCrop * 272.0f);
 					return;
 				}
 			}
@@ -102,10 +102,10 @@ void CenterDisplayOutputRect(float *x, float *y, float *w, float *h, float origW
 		}
 	}
 
-	*x = (frameW - outW) / 2.0f;
-	*y = (frameH - outH) / 2.0f;
-	*w = outW;
-	*h = outH;
+	*x = floorf((frameW - outW) / 2.0f);
+	*y = floorf((frameH - outH) / 2.0f);
+	*w = floorf(outW);
+	*h = floorf(outH);
 }
 
 
diff --git a/GPU/GLES/Framebuffer.cpp b/GPU/GLES/Framebuffer.cpp
index 3124ed125402..b5477dd0bef7 100644
--- a/GPU/GLES/Framebuffer.cpp
+++ b/GPU/GLES/Framebuffer.cpp
@@ -210,8 +210,6 @@ void FramebufferManager::CompileDraw2DProgram() {
 				deltaLoc_ = glsl_uniform_loc(postShaderProgram_, "u_texelDelta");
 				pixelDeltaLoc_ = glsl_uniform_loc(postShaderProgram_, "u_pixelDelta");
 				timeLoc_ = glsl_uniform_loc(postShaderProgram_, "u_time");
-
-				UpdatePostShaderUniforms(renderWidth_, renderHeight_);
 				usePostShader_ = true;
 			}
 		} else {
@@ -223,7 +221,7 @@ void FramebufferManager::CompileDraw2DProgram() {
 	}
 }
 
-void FramebufferManager::UpdatePostShaderUniforms(int renderWidth, int renderHeight) {
+void FramebufferManager::UpdatePostShaderUniforms(int bufferWidth, int bufferHeight, int renderWidth, int renderHeight) {
 	float u_delta = 1.0f / renderWidth;
 	float v_delta = 1.0f / renderHeight;
 	float u_pixel_delta = u_delta;
@@ -231,8 +229,8 @@ void FramebufferManager::UpdatePostShaderUniforms(int renderWidth, int renderHei
 	if (postShaderAtOutputResolution_) {
 		float x, y, w, h;
 		CenterDisplayOutputRect(&x, &y, &w, &h, 480.0f, 272.0f, (float)pixelWidth_, (float)pixelHeight_, ROTATION_LOCKED_HORIZONTAL, false);
-		u_pixel_delta = 1.0f / w;
-		v_pixel_delta = 1.0f / h;
+		u_pixel_delta = (1.0f / w) * (480.0f / bufferWidth);
+		v_pixel_delta = (1.0f / h) * (272.0f / bufferHeight);
 	}
 
 	if (deltaLoc_ != -1)
@@ -427,7 +425,7 @@ void FramebufferManager::DrawFramebufferToOutput(const u8 *srcPixels, GEBufferFo
 	CenterDisplayOutputRect(&x, &y, &w, &h, 480.0f, 272.0f, (float)pixelWidth_, (float)pixelHeight_, uvRotation, true);
 	if (applyPostShader) {
 		glsl_bind(postShaderProgram_);
-		UpdatePostShaderUniforms(renderWidth_, renderHeight_);
+		UpdatePostShaderUniforms(480, 272, renderWidth_, renderHeight_);
 	}
 	float u0 = 0.0f, u1 = 480.0f / 512.0f;
 	float v0 = 0.0f, v1 = 1.0f;
@@ -1089,7 +1087,7 @@ void FramebufferManager::CopyDisplayToOutput() {
 			glstate.viewport.set(0, 0, fbo_w, fbo_h);
 			shaderManager_->DirtyLastShader();  // dirty lastShader_
 			glsl_bind(postShaderProgram_);
-			UpdatePostShaderUniforms(renderWidth_, renderHeight_);
+			UpdatePostShaderUniforms(vfb->bufferWidth, vfb->bufferHeight, renderWidth_, renderHeight_);
 			DrawActiveTexture(colorTexture, 0, 0, fbo_w, fbo_h, fbo_w, fbo_h, 0.0f, 0.0f, 1.0f, 1.0f, postShaderProgram_, ROTATION_LOCKED_HORIZONTAL);
 
 			fbo_unbind();
@@ -1132,7 +1130,7 @@ void FramebufferManager::CopyDisplayToOutput() {
 
 			shaderManager_->DirtyLastShader();  // dirty lastShader_
 			glsl_bind(postShaderProgram_);
-			UpdatePostShaderUniforms(vfb->renderWidth, vfb->renderHeight);
+			UpdatePostShaderUniforms(vfb->bufferWidth, vfb->bufferHeight, vfb->renderWidth, vfb->renderHeight);
 			if (g_Config.bEnableCardboard) {
 				// Left Eye Image
 				glstate.viewport.set(cardboardSettings.leftEyeXPosition, cardboardSettings.screenYPosition, cardboardSettings.screenWidth, cardboardSettings.screenHeight);
diff --git a/GPU/GLES/Framebuffer.h b/GPU/GLES/Framebuffer.h
index b1b53efb782f..4acc4c884c3a 100644
--- a/GPU/GLES/Framebuffer.h
+++ b/GPU/GLES/Framebuffer.h
@@ -137,7 +137,7 @@ class FramebufferManager : public FramebufferManagerCommon {
 	virtual void NotifyRenderFramebufferUpdated(VirtualFramebuffer *vfb, bool vfbFormatChanged) override;
 
 private:
-	void UpdatePostShaderUniforms(int renderWidth, int renderHeight);
+	void UpdatePostShaderUniforms(int bufferWidth, int bufferHeight, int renderWidth, int renderHeight);
 	void CompileDraw2DProgram();
 	void DestroyDraw2DProgram();