diff --git a/gdk/gdkmemorytexture.c b/gdk/gdkmemorytexture.c
index 9dc0321f1b..e439ca2d99 100644
--- a/gdk/gdkmemorytexture.c
+++ b/gdk/gdkmemorytexture.c
@@ -225,15 +225,15 @@ gdk_memory_texture_new_subtexture (GdkMemoryTexture  *source,
   GBytes *bytes;
 
   g_return_val_if_fail (GDK_IS_MEMORY_TEXTURE (source), NULL);
-  g_return_val_if_fail (x < 0 || x >= GDK_TEXTURE (source)->width, NULL);
-  g_return_val_if_fail (y < 0 || y >= GDK_TEXTURE (source)->height, NULL);
-  g_return_val_if_fail (width <= 0 || x + width > GDK_TEXTURE (source)->width, NULL);
-  g_return_val_if_fail (height <= 0 || y + height > GDK_TEXTURE (source)->height, NULL);
+  g_return_val_if_fail (x >= 0 || x < GDK_TEXTURE (source)->width, NULL);
+  g_return_val_if_fail (y >= 0 || y < GDK_TEXTURE (source)->height, NULL);
+  g_return_val_if_fail (width > 0 || x + width <= GDK_TEXTURE (source)->width, NULL);
+  g_return_val_if_fail (height > 0 || y + height <= GDK_TEXTURE (source)->height, NULL);
 
   texture = GDK_TEXTURE (source);
   bpp = gdk_memory_format_bytes_per_pixel (texture->format);
   offset = y * source->stride + x * bpp;
-  size = source->stride * (height - 1) + x * bpp;
+  size = source->stride * (height - 1) + width * bpp;
   bytes = g_bytes_new_from_bytes (source->bytes, offset, size);
 
   result = gdk_memory_texture_new (texture->width,