diff --git a/ChangeLog b/ChangeLog
index 293bc9884..b590def26 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+2018-05-15  Alexei Podtelezhnikov  <apodtele@gmail.com>
+
+	[base] Fix mono bitmap presetting (#53896).
+
+	It is rather fundamental to set monochrome bitmap based on rounded
+	CBox because the b/w rasterizer turns on pixels when their centers are
+	inside the glyph outline. The dropout control is unpredictable and can
+	distort narrow glyphs if the bitmap is too wide.
+
+	Reported by Chris Liddell.
+
+	* src/base/ftobjs.c (ft_glyphslot_preset_bitmap): If BBox boundaries
+	are too close, adjust them before rounding.
+
 2018-05-15  Werner Lemberg  <wl@gnu.org>
 
 	[psaux] Fix compiler warning (#53915).
diff --git a/src/base/ftobjs.c b/src/base/ftobjs.c
index c102bbea5..05e2a038a 100644
--- a/src/base/ftobjs.c
+++ b/src/base/ftobjs.c
@@ -374,32 +374,26 @@
       /* unless the rounded box can collapse for a narrow glyph */
       if ( cbox.xMax - cbox.xMin < 64 )
       {
-        cbox.xMin = FT_PIX_FLOOR( cbox.xMin );
-        cbox.xMax = FT_PIX_CEIL_LONG( cbox.xMax );
-      }
-      else
-      {
-        cbox.xMin = FT_PIX_ROUND_LONG( cbox.xMin );
-        cbox.xMax = FT_PIX_ROUND_LONG( cbox.xMax );
+        cbox.xMin = ( cbox.xMin + cbox.xMax ) / 2 - 32;
+        cbox.xMax = cbox.xMin + 64;
       }
 
+      cbox.xMin = FT_PIX_ROUND_LONG( cbox.xMin );
+      cbox.xMax = FT_PIX_ROUND_LONG( cbox.xMax );
+
       if ( cbox.yMax - cbox.yMin < 64 )
       {
-        cbox.yMin = FT_PIX_FLOOR( cbox.yMin );
-        cbox.yMax = FT_PIX_CEIL_LONG( cbox.yMax );
+        cbox.yMin = ( cbox.yMin + cbox.yMax ) / 2 - 32;
+        cbox.yMax = cbox.yMin + 64;
       }
-      else
-      {
-        cbox.yMin = FT_PIX_ROUND_LONG( cbox.yMin );
-        cbox.yMax = FT_PIX_ROUND_LONG( cbox.yMax );
-      }
-#else
-      cbox.xMin = FT_PIX_FLOOR( cbox.xMin );
-      cbox.yMin = FT_PIX_FLOOR( cbox.yMin );
-      cbox.xMax = FT_PIX_CEIL_LONG( cbox.xMax );
-      cbox.yMax = FT_PIX_CEIL_LONG( cbox.yMax );
-#endif
+
+      cbox.yMin = FT_PIX_ROUND_LONG( cbox.yMin );
+      cbox.yMax = FT_PIX_ROUND_LONG( cbox.yMax );
+
       break;
+#else
+      goto Round;
+#endif
 
     case FT_RENDER_MODE_LCD:
       pixel_mode = FT_PIXEL_MODE_LCD;