diff --git a/Libraries/LibDraw/GraphicsBitmap.cpp b/Libraries/LibDraw/GraphicsBitmap.cpp
index 354c94eb66..77fad40f25 100644
--- a/Libraries/LibDraw/GraphicsBitmap.cpp
+++ b/Libraries/LibDraw/GraphicsBitmap.cpp
@@ -24,9 +24,9 @@ GraphicsBitmap::GraphicsBitmap(Format format, const Size& size)
     m_needs_munmap = true;
 }
 
-NonnullRefPtr<GraphicsBitmap> GraphicsBitmap::create_wrapper(Format format, const Size& size, RGBA32* data)
+NonnullRefPtr<GraphicsBitmap> GraphicsBitmap::create_wrapper(Format format, const Size& size, size_t pitch, RGBA32* data)
 {
-    return adopt(*new GraphicsBitmap(format, size, data));
+    return adopt(*new GraphicsBitmap(format, size, pitch, data));
 }
 
 RefPtr<GraphicsBitmap> GraphicsBitmap::load_from_file(const StringView& path)
@@ -42,10 +42,10 @@ RefPtr<GraphicsBitmap> GraphicsBitmap::load_from_file(Format format, const Strin
     return adopt(*new GraphicsBitmap(format, size, move(mapped_file)));
 }
 
-GraphicsBitmap::GraphicsBitmap(Format format, const Size& size, RGBA32* data)
+GraphicsBitmap::GraphicsBitmap(Format format, const Size& size, size_t pitch, RGBA32* data)
     : m_size(size)
     , m_data(data)
-    , m_pitch(round_up_to_power_of_two(size.width() * sizeof(RGBA32), 16))
+    , m_pitch(pitch)
     , m_format(format)
 {
     ASSERT(format != Format::Indexed8);
diff --git a/Libraries/LibDraw/GraphicsBitmap.h b/Libraries/LibDraw/GraphicsBitmap.h
index cfd056390a..b126597871 100644
--- a/Libraries/LibDraw/GraphicsBitmap.h
+++ b/Libraries/LibDraw/GraphicsBitmap.h
@@ -20,7 +20,7 @@ public:
     };
 
     static NonnullRefPtr<GraphicsBitmap> create(Format, const Size&);
-    static NonnullRefPtr<GraphicsBitmap> create_wrapper(Format, const Size&, RGBA32*);
+    static NonnullRefPtr<GraphicsBitmap> create_wrapper(Format, const Size&, size_t pitch, RGBA32*);
     static RefPtr<GraphicsBitmap> load_from_file(const StringView& path);
     static RefPtr<GraphicsBitmap> load_from_file(Format, const StringView& path, const Size&);
     static NonnullRefPtr<GraphicsBitmap> create_with_shared_buffer(Format, NonnullRefPtr<SharedBuffer>&&, const Size&);
@@ -94,7 +94,7 @@ public:
 
 private:
     GraphicsBitmap(Format, const Size&);
-    GraphicsBitmap(Format, const Size&, RGBA32*);
+    GraphicsBitmap(Format, const Size&, size_t pitch, RGBA32*);
     GraphicsBitmap(Format, const Size&, MappedFile&&);
     GraphicsBitmap(Format, NonnullRefPtr<SharedBuffer>&&, const Size&);
 
diff --git a/Servers/WindowServer/WSCompositor.cpp b/Servers/WindowServer/WSCompositor.cpp
index f1221f5c1a..9bd01cda7c 100644
--- a/Servers/WindowServer/WSCompositor.cpp
+++ b/Servers/WindowServer/WSCompositor.cpp
@@ -60,12 +60,15 @@ WSCompositor::WSCompositor()
 
 void WSCompositor::init_bitmaps()
 {
-    auto size = WSScreen::the().size();
+    auto& screen = WSScreen::the();
+    auto size = screen.size();
 
-    m_front_bitmap = GraphicsBitmap::create_wrapper(GraphicsBitmap::Format::RGB32, size, WSScreen::the().scanline(0));
+    m_front_bitmap = GraphicsBitmap::create_wrapper(GraphicsBitmap::Format::RGB32, size, screen.pitch(), screen.scanline(0));
+
+    ASSERT(m_screen_can_set_buffer);
 
     if (m_screen_can_set_buffer)
-        m_back_bitmap = GraphicsBitmap::create_wrapper(GraphicsBitmap::Format::RGB32, size, WSScreen::the().scanline(size.height()));
+        m_back_bitmap = GraphicsBitmap::create_wrapper(GraphicsBitmap::Format::RGB32, size, screen.pitch(), screen.scanline(size.height()));
     else
         m_back_bitmap = GraphicsBitmap::create(GraphicsBitmap::Format::RGB32, size);
 
diff --git a/Servers/WindowServer/WSScreen.h b/Servers/WindowServer/WSScreen.h
index e5ff7451f4..b2bacfaf42 100644
--- a/Servers/WindowServer/WSScreen.h
+++ b/Servers/WindowServer/WSScreen.h
@@ -16,6 +16,7 @@ public:
 
     int width() const { return m_width; }
     int height() const { return m_height; }
+    size_t pitch() const { return m_pitch; }
     RGBA32* scanline(int y);
 
     static WSScreen& the();