diff --git a/ChangeLog b/ChangeLog
index 6450a60be..de4ea869d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,24 @@
+2019-07-04  Chris Liddell <chris.liddell@artifex.com>
+
+	[psaux] (1/2) Handle fonts that use SEAC for ligatures (#56580).
+
+	As originally intended, a Type 1 SEAC charstring would be used for
+	an accented glyph (like `acaron' or `uumlaut'), where the advance
+	width of the SEAC glyph is the same as that of the `base' glyph
+	(like `a' or `u').  In this case it is not uncommon for the SEAC
+	glyph to not use an (H)SBW opcode of its own but to rely on the
+	value from the base glyph.
+
+	However, out-of-spec fonts also use SEAC glyphs for ligatures (like
+	`oe' or `fi'), and in those cases the overall advance width is
+	greater than that of the `base' glyph.  For this reason we have to
+	allow that the SEAC glyph can have an (H)SBW value of its own, and
+	if it has, retain this value, rather than the one from the base
+	glyph.
+
+	* src/psaux/psintrp.c (cf2_interpT2CharString) <cf2_escSEAC>:
+	Implement it.
+
 2019-07-01  Werner Lemberg  <wl@gnu.org>
 
 	* Version 2.10.1 released.
diff --git a/src/psaux/psintrp.c b/src/psaux/psintrp.c
index e2f3accdd..0a8414553 100644
--- a/src/psaux/psintrp.c
+++ b/src/psaux/psintrp.c
@@ -1433,6 +1433,13 @@
                       lastError = error2; /* pass FreeType error through */
                       goto exit;
                     }
+
+                    /* save the left bearing and width of the SEAC   */
+                    /* glyph as they will be erased by the next load */
+
+                    left_bearing = *decoder->builder.left_bearing;
+                    advance      = *decoder->builder.advance;
+
                     cf2_interpT2CharString( font,
                                             &component,
                                             callbacks,
@@ -1443,11 +1450,14 @@
                                             &dummyWidth );
                     cf2_freeT1SeacComponent( decoder, &component );
 
-                    /* save the left bearing and width of the base       */
-                    /* character as they will be erased by the next load */
+                    /* If the SEAC glyph doesn't have a (H)SBW of its */
+                    /* own use the values from the base glyph.        */
 
-                    left_bearing = *decoder->builder.left_bearing;
-                    advance      = *decoder->builder.advance;
+                    if ( !haveWidth )
+                    {
+                      left_bearing = *decoder->builder.left_bearing;
+                      advance      = *decoder->builder.advance;
+                    }
 
                     decoder->builder.left_bearing->x = 0;
                     decoder->builder.left_bearing->y = 0;
@@ -1473,8 +1483,8 @@
                                             &dummyWidth );
                     cf2_freeT1SeacComponent( decoder, &component );
 
-                    /* restore the left side bearing and   */
-                    /* advance width of the base character */
+                    /* restore the left side bearing and advance width   */
+                    /* of the SEAC glyph or base character (saved above) */
 
                     *decoder->builder.left_bearing = left_bearing;
                     *decoder->builder.advance      = advance;