diff --git a/src/hb-font.cc b/src/hb-font.cc
index dd1a31508..1c6a41011 100644
--- a/src/hb-font.cc
+++ b/src/hb-font.cc
@@ -1478,6 +1478,7 @@ DEFINE_NULL_INSTANCE (hb_font_t) =
   1000, /* x_scale */
   1000, /* y_scale */
   0., /* slant */
+  0., /* slant_xy; */
   1<<16, /* x_mult */
   1<<16, /* y_mult */
 
diff --git a/src/hb-font.hh b/src/hb-font.hh
index 248d85deb..0d73589e8 100644
--- a/src/hb-font.hh
+++ b/src/hb-font.hh
@@ -110,6 +110,7 @@ struct hb_font_t
   int32_t x_scale;
   int32_t y_scale;
   float slant;
+  float slant_xy;
   int64_t x_mult;
   int64_t y_mult;
 
@@ -618,6 +619,7 @@ struct hb_font_t
     signed upem = face->get_upem ();
     x_mult = ((int64_t) x_scale << 16) / upem;
     y_mult = ((int64_t) y_scale << 16) / upem;
+    slant_xy = y_scale ? slant * x_scale / y_scale : 0.f;
   }
 
   hb_position_t em_mult (int16_t v, int64_t mult)
diff --git a/src/hb-ot-layout-gpos-table.hh b/src/hb-ot-layout-gpos-table.hh
index 6db3e0894..bda6f02b8 100644
--- a/src/hb-ot-layout-gpos-table.hh
+++ b/src/hb-ot-layout-gpos-table.hh
@@ -2951,7 +2951,7 @@ GPOS::position_finish_advances (hb_font_t *font HB_UNUSED, hb_buffer_t *buffer H
 }
 
 void
-GPOS::position_finish_offsets (hb_font_t *font HB_UNUSED, hb_buffer_t *buffer)
+GPOS::position_finish_offsets (hb_font_t *font, hb_buffer_t *buffer)
 {
   _hb_buffer_assert_gsubgpos_vars (buffer);
 
@@ -2961,8 +2961,15 @@ GPOS::position_finish_offsets (hb_font_t *font HB_UNUSED, hb_buffer_t *buffer)
 
   /* Handle attachments */
   if (buffer->scratch_flags & HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT)
-    for (unsigned int i = 0; i < len; i++)
+    for (unsigned i = 0; i < len; i++)
       propagate_attachment_offsets (pos, len, i, direction);
+
+  if (unlikely (font->slant))
+  {
+    for (unsigned i = 0; i < len; i++)
+      if (unlikely (pos[i].y_offset))
+        pos[i].x_offset += _hb_roundf (font->slant_xy * pos[i].y_offset);
+  }
 }