diff --git a/Cocoa/Document.m b/Cocoa/Document.m
index 5fe30c1..f4abb5b 100644
--- a/Cocoa/Document.m
+++ b/Cocoa/Document.m
@@ -314,6 +314,8 @@ static void printImage(GB_gameboy_t *gb, uint32_t *image, uint8_t height,
     NSMutableParagraphStyle *paragraph_style = [[NSMutableParagraphStyle alloc] init];
     [paragraph_style setLineSpacing:2];
     
+    self.mainWindow.backgroundColor = [NSColor blackColor];
+    
     self.debuggerSideViewInput.font = [NSFont userFixedPitchFontOfSize:12];
     self.debuggerSideViewInput.textColor = [NSColor whiteColor];
     self.debuggerSideViewInput.defaultParagraphStyle = paragraph_style;
diff --git a/Cocoa/Document.xib b/Cocoa/Document.xib
index 88c5275..5694ecd 100644
--- a/Cocoa/Document.xib
+++ b/Cocoa/Document.xib
@@ -50,16 +50,10 @@
                 <rect key="frame" x="0.0" y="0.0" width="160" height="144"/>
                 <autoresizingMask key="autoresizingMask"/>
                 <subviews>
-                    <customView id="KTk-4M-J7t" customClass="GBBorderView">
+                    <view id="uqf-pe-VAF" customClass="GBView">
                         <rect key="frame" x="0.0" y="0.0" width="160" height="144"/>
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
-                        <subviews>
-                            <view id="uqf-pe-VAF" customClass="GBView">
-                                <rect key="frame" x="0.0" y="0.0" width="160" height="144"/>
-                                <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
-                            </view>
-                        </subviews>
-                    </customView>
+                    </view>
                 </subviews>
             </view>
             <connections>
diff --git a/Cocoa/GBBorderView.h b/Cocoa/GBBorderView.h
deleted file mode 100644
index 477add1..0000000
--- a/Cocoa/GBBorderView.h
+++ /dev/null
@@ -1,5 +0,0 @@
-#import <Cocoa/Cocoa.h>
-
-@interface GBBorderView : NSView
-
-@end
diff --git a/Cocoa/GBBorderView.m b/Cocoa/GBBorderView.m
deleted file mode 100644
index c81adb4..0000000
--- a/Cocoa/GBBorderView.m
+++ /dev/null
@@ -1,11 +0,0 @@
-#import "GBBorderView.h"
-
-@implementation GBBorderView
-
-- (void)drawRect:(NSRect)dirtyRect {
-    [[NSColor blackColor] setFill];
-    NSRectFill(dirtyRect);
-    [super drawRect:dirtyRect];
-}
-
-@end
diff --git a/Cocoa/GBViewMetal.m b/Cocoa/GBViewMetal.m
index 34cd50b..1c0a86f 100644
--- a/Cocoa/GBViewMetal.m
+++ b/Cocoa/GBViewMetal.m
@@ -71,6 +71,13 @@ static const vector_float2 rect[] =
     [self loadShader];
 }
 
+- (void)addSubview:(NSView *)view
+{
+    /* Fixes rounded corners */
+    [super addSubview:view];
+    [self setWantsLayer:YES];
+}
+
 - (void) loadShader
 {
     NSError *error = nil;