diff --git a/bsnes/sfc/ppu-fast/background.cpp b/bsnes/sfc/ppu-fast/background.cpp
index ffa6867c..a9863431 100644
--- a/bsnes/sfc/ppu-fast/background.cpp
+++ b/bsnes/sfc/ppu-fast/background.cpp
@@ -28,13 +28,13 @@ auto PPU::Line::renderBackground(PPU::IO::Background& self, uint8 source) -> voi
   uint vmask = (width << self.tileSize << !!(self.screenSize & 2)) - 1;
 
   uint y = this->y;
-  if(self.mosaicEnable) y -= io.mosaic.size - io.mosaic.counter;
+
   if(hires) {
     hscroll <<= 1;
-    if(io.interlace) {
-      y = y << 1 | field();
-      if(self.mosaicEnable) y -= io.mosaic.size - io.mosaic.counter + field();
-    }
+    if(io.interlace) y = y << 1 | (field() && !self.mosaicEnable);
+  }
+  if(self.mosaicEnable) {
+    y -= (io.mosaic.size - io.mosaic.counter) << (hires && io.interlace);
   }
 
   uint mosaicCounter = 1;
@@ -112,7 +112,7 @@ auto PPU::Line::renderBackground(PPU::IO::Background& self, uint8 source) -> voi
           color += data >> shift + 49 & 128;
         }
 
-        mosaicCounter = self.mosaicEnable ? io.mosaic.size : 1;
+        mosaicCounter = self.mosaicEnable ? io.mosaic.size << hires : 1;
         mosaicPalette = color;
         mosaicPriority = tilePriority;
         if(directColorMode) {
diff --git a/bsnes/sfc/ppu/background.cpp b/bsnes/sfc/ppu/background.cpp
index dcf3cc9d..e9d3dcb3 100644
--- a/bsnes/sfc/ppu/background.cpp
+++ b/bsnes/sfc/ppu/background.cpp
@@ -37,13 +37,12 @@ auto PPU::Background::fetchNameTable() -> void {
   uint hscroll = io.hoffset;
   uint vscroll = io.voffset;
 
-  if(mosaic.enable) vpixel -= ppu.mosaic.voffset();
   if(hires()) {
     hscroll <<= 1;
-    if(ppu.io.interlace) {
-      vpixel = vpixel << 1 | ppu.field();
-      if(mosaic.enable) vpixel -= ppu.mosaic.voffset() + ppu.field();
-    }
+    if(ppu.io.interlace) vpixel = vpixel << 1 | (ppu.field() && !mosaic.enable);
+  }
+  if(mosaic.enable) {
+    vpixel -= ppu.mosaic.voffset() << (hires() && ppu.io.interlace);
   }
 
   bool repeated = false;
@@ -197,7 +196,8 @@ auto PPU::Background::run(bool screen) -> void {
   if(++pixelCounter == 0) renderingIndex++;
 
   uint x = ppu.hcounter() - 56 >> 2;
-  if(x == 0) {
+
+  if(x == 0 && (!hires() || screen == Screen::Below)) {
     mosaic.hcounter = ppu.mosaic.size;
     mosaic.pixel = pixel;
   } else if((!hires() || screen == Screen::Below) && --mosaic.hcounter == 0) {