diff --git a/ChangeLog b/ChangeLog
index 03292f1ac..bed580216 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2019-09-17  Werner Lemberg  <wl@gnu.org>
+
+	* src/otvalid/otvcommon.c (otv_Coverage_get_last): Guard `count'.
+
+	Problem reported by Marc Schönefeld <marc.schoenefeld@gmx.org>.
+
 2019-09-17  Werner Lemberg  <wl@gnu.org>
 
 	* src/sfnt/sfwoff2.c (woff2_open_font): Check table index.
diff --git a/src/otvalid/otvcommn.c b/src/otvalid/otvcommn.c
index 5ed172350..3bd99f504 100644
--- a/src/otvalid/otvcommn.c
+++ b/src/otvalid/otvcommn.c
@@ -151,6 +151,9 @@
     FT_UInt   result = 0;
 
 
+    if ( !count )
+      return result;
+
     switch ( CoverageFormat )
     {
     case 1: