diff --git a/ChangeLog b/ChangeLog
index d5fc9c251..82d6f2c2d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2017-11-22  Ewald Hew  <ewaldhew@gmail.com>
+
+	* src/psaux/psft.c (cf2_setGlyphWidth): Check format before setting.
+
+	Reported as
+
+	  https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=4377
+
 2017-11-22  Ewald Hew  <ewaldhew@gmail.com>
 
 	[psaux] Fix CFF advance widths. (#52466)
diff --git a/src/psaux/psft.c b/src/psaux/psft.c
index 0f9bdd9c6..bd5f831f4 100644
--- a/src/psaux/psft.c
+++ b/src/psaux/psft.c
@@ -95,7 +95,8 @@
 
     FT_ASSERT( decoder );
 
-    *decoder->glyph_width = cf2_fixedToInt( width );
+    if ( !decoder->builder.is_t1 )
+      *decoder->glyph_width = cf2_fixedToInt( width );
   }