diff --git a/src/cairo-pdf-surface.c b/src/cairo-pdf-surface.c
index 91a1968..9f099ae 100644
--- a/src/cairo-pdf-surface.c
+++ b/src/cairo-pdf-surface.c
@@ -274,7 +274,7 @@ _cairo_pdf_surface_create_for_stream_int
     _cairo_array_init (&surface->streams, sizeof (cairo_pdf_resource_t));
     _cairo_array_init (&surface->alphas, sizeof (double));
 
-    surface->font_subsets = _cairo_scaled_font_subsets_create (PDF_SURFACE_MAX_GLYPHS_PER_FONT);
+    surface->font_subsets = _cairo_scaled_font_subsets_create (PDF_SURFACE_MAX_GLYPHS_PER_FONT, TRUE);
     if (! surface->font_subsets) {
 	_cairo_error (CAIRO_STATUS_NO_MEMORY);
 	free (surface);
diff --git a/src/cairo-ps-surface.c b/src/cairo-ps-surface.c
index 6ae3a38..f1151c2 100644
--- a/src/cairo-ps-surface.c
+++ b/src/cairo-ps-surface.c
@@ -761,7 +761,7 @@ _cairo_ps_surface_create_for_stream_inte
     if (status)
 	goto CLEANUP_TMPFILE;
 
-    surface->font_subsets = _cairo_scaled_font_subsets_create (PS_SURFACE_MAX_GLYPHS_PER_FONT);
+    surface->font_subsets = _cairo_scaled_font_subsets_create (PS_SURFACE_MAX_GLYPHS_PER_FONT, TRUE);
     if (! surface->font_subsets)
 	goto CLEANUP_OUTPUT_STREAM;
 
diff --git a/src/cairo-scaled-font-subsets-private.h b/src/cairo-scaled-font-subsets-private.h
index c41e477..6d0e942 100644
--- a/src/cairo-scaled-font-subsets-private.h
+++ b/src/cairo-scaled-font-subsets-private.h
@@ -58,6 +58,8 @@ typedef struct _cairo_scaled_font_subset
  * @max_glyphs_per_subset: the maximum number of glyphs that should
  * appear in any subset. A value of 0 indicates that there is no limit
  * to the number of glyphs per subset.
+ * @merge_scaled: merge all scaled fonts with the same face into
+ * the same subset.
  *
  * Create a new #cairo_scaled_font_subsets_t object which can be used
  * to create subsets of any number of cairo_scaled_font_t
@@ -71,7 +73,7 @@ typedef struct _cairo_scaled_font_subset
  * _cairo_scaled_font_subsets_destroy() when done with it.
  **/
 cairo_private cairo_scaled_font_subsets_t *
-_cairo_scaled_font_subsets_create (int max_glyphs_per_subset);
+_cairo_scaled_font_subsets_create (int max_glyphs_per_subset, cairo_bool_t merge_scaled);
 
 /**
  * _cairo_scaled_font_subsets_destroy:
diff --git a/src/cairo-scaled-font-subsets.c b/src/cairo-scaled-font-subsets.c
index 0c428e7..1623536 100644
--- a/src/cairo-scaled-font-subsets.c
+++ b/src/cairo-scaled-font-subsets.c
@@ -46,6 +46,7 @@ struct _cairo_scaled_font_subsets {
     int max_glyphs_per_subset_limit;
     int max_glyphs_per_subset_used;
     int num_sub_fonts;
+    cairo_bool_t merge_scaled;
 
     cairo_hash_table_t *sub_fonts;
 };
@@ -163,14 +164,20 @@ _cairo_sub_fonts_equal (const void *key_
     const cairo_sub_font_t *sub_font_a = key_a;
     const cairo_sub_font_t *sub_font_b = key_b;
 
-    return sub_font_a->scaled_font == sub_font_b->scaled_font;
+    if (sub_font_a->parent->merge_scaled)
+        return sub_font_a->scaled_font->font_face == sub_font_b->scaled_font->font_face;
+    else
+        return sub_font_a->scaled_font == sub_font_b->scaled_font;
 }
 
 static void
 _cairo_sub_font_init_key (cairo_sub_font_t	*sub_font,
 			  cairo_scaled_font_t	*scaled_font)
 {
-    sub_font->base.hash = (unsigned long) scaled_font;
+    if (sub_font->parent->merge_scaled)
+        sub_font->base.hash = (unsigned long) scaled_font->font_face;
+    else
+        sub_font->base.hash = (unsigned long) scaled_font;
     sub_font->scaled_font = scaled_font;
 }
 
@@ -186,9 +193,9 @@ _cairo_sub_font_create (cairo_scaled_fon
     if (sub_font == NULL)
 	return NULL;
 
+    sub_font->parent = parent;
     _cairo_sub_font_init_key (sub_font, scaled_font);
 
-    sub_font->parent = parent;
     sub_font->scaled_font = cairo_scaled_font_reference (scaled_font);
     sub_font->font_id = font_id;
 
@@ -298,7 +305,7 @@ _cairo_sub_font_collect (void *entry, vo
 }
 
 cairo_scaled_font_subsets_t *
-_cairo_scaled_font_subsets_create (int max_glyphs_per_subset)
+_cairo_scaled_font_subsets_create (int max_glyphs_per_subset, cairo_bool_t merge_scaled)
 {
     cairo_scaled_font_subsets_t *subsets;
 
@@ -309,6 +316,7 @@ _cairo_scaled_font_subsets_create (int m
     subsets->max_glyphs_per_subset_limit = max_glyphs_per_subset;
     subsets->max_glyphs_per_subset_used = 0;
     subsets->num_sub_fonts = 0;
+    subsets->merge_scaled = merge_scaled;
 
     subsets->sub_fonts = _cairo_hash_table_create (_cairo_sub_fonts_equal);
     if (! subsets->sub_fonts) {
diff --git a/src/cairo-svg-surface.c b/src/cairo-svg-surface.c
index abc1ec3..55ed08a 100644
--- a/src/cairo-svg-surface.c
+++ b/src/cairo-svg-surface.c
@@ -1697,7 +1697,7 @@ _cairo_svg_document_create (cairo_output
     }
 
     /* The use of defs for font glyphs imposes no per-subset limit. */
-    document->font_subsets = _cairo_scaled_font_subsets_create (0);
+    document->font_subsets = _cairo_scaled_font_subsets_create (0, FALSE);
     if (document->font_subsets == NULL) {
 	_cairo_error (CAIRO_STATUS_NO_MEMORY);
 	free (document);