diff --git a/ChangeLog b/ChangeLog
index b5069b1c1..e50665b1e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,16 @@
+2017-06-16  Werner Lemberg  <wl@gnu.org>
+
+	[cff, truetype] Integer overflows.
+
+	Reported as
+
+	  https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=2300
+	  https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=2313
+
+	* src/cff/cf2hints.c (cf2_hintmap_adjustHints): Use ADD_INT32.
+
+	* src/truetype/ttinterp.c (Ins_ABS): Avoid FT_ABS.
+
 2017-06-17  Alexei Podtelezhnikov  <apodtele@gmail.com>
 
 	[base, smooth] LCD filtering cleanups.
diff --git a/src/cff/cf2hints.c b/src/cff/cf2hints.c
index 0951e1e7a..e0f2cc91c 100644
--- a/src/cff/cf2hints.c
+++ b/src/cff/cf2hints.c
@@ -440,14 +440,16 @@
         /* is there room to move up?                                    */
         /* there is if we are at top of array or the next edge is at or */
         /* beyond proposed move up?                                     */
-        if ( j >= hintmap->count - 1                            ||
+        if ( j >= hintmap->count - 1                ||
              hintmap->edge[j + 1].dsCoord >=
-               hintmap->edge[j].dsCoord + moveUp + upMinCounter )
+               ADD_INT32( hintmap->edge[j].dsCoord,
+                          moveUp + upMinCounter )   )
         {
           /* there is room to move up; is there also room to move down? */
-          if ( i == 0                                                 ||
+          if ( i == 0                                   ||
                hintmap->edge[i - 1].dsCoord <=
-                 hintmap->edge[i].dsCoord + moveDown - downMinCounter )
+                 ADD_INT32( hintmap->edge[i].dsCoord,
+                            moveDown - downMinCounter ) )
           {
             /* move smaller absolute amount */
             move = ( -moveDown < moveUp ) ? moveDown : moveUp;  /* optimum */
@@ -458,9 +460,10 @@
         else
         {
           /* is there room to move down? */
-          if ( i == 0                                                 ||
+          if ( i == 0                                   ||
                hintmap->edge[i - 1].dsCoord <=
-                 hintmap->edge[i].dsCoord + moveDown - downMinCounter )
+                 ADD_INT32( hintmap->edge[i].dsCoord,
+                            moveDown - downMinCounter ) )
           {
             move     = moveDown;
             /* true if non-optimum move */
@@ -494,9 +497,11 @@
         }
 
         /* move the edge(s) */
-        hintmap->edge[i].dsCoord += move;
+        hintmap->edge[i].dsCoord = ADD_INT32( hintmap->edge[i].dsCoord,
+                                              move );
         if ( isPair )
-          hintmap->edge[j].dsCoord += move;
+          hintmap->edge[j].dsCoord = ADD_INT32( hintmap->edge[j].dsCoord,
+                                                move );
       }
 
       /* assert there are no overlaps in device space */
@@ -544,15 +549,18 @@
 
       /* is there room to move up? */
       if ( hintmap->edge[j + 1].dsCoord >=
-             hintmap->edge[j].dsCoord + hintMove->moveUp + CF2_MIN_COUNTER )
+             ADD_INT32( hintmap->edge[j].dsCoord,
+                        hintMove->moveUp + CF2_MIN_COUNTER ) )
       {
         /* there is more room now, move edge up */
-        hintmap->edge[j].dsCoord += hintMove->moveUp;
+        hintmap->edge[j].dsCoord = ADD_INT32( hintmap->edge[j].dsCoord,
+                                              hintMove->moveUp );
 
         if ( cf2_hint_isPair( &hintmap->edge[j] ) )
         {
           FT_ASSERT( j > 0 );
-          hintmap->edge[j - 1].dsCoord += hintMove->moveUp;
+          hintmap->edge[j - 1].dsCoord =
+            ADD_INT32( hintmap->edge[j - 1].dsCoord, hintMove->moveUp );
         }
       }
     }
diff --git a/src/truetype/ttinterp.c b/src/truetype/ttinterp.c
index bf198f77c..c6605bb92 100644
--- a/src/truetype/ttinterp.c
+++ b/src/truetype/ttinterp.c
@@ -2914,7 +2914,8 @@
   static void
   Ins_ABS( FT_Long*  args )
   {
-    args[0] = FT_ABS( args[0] );
+    if ( args[0] < 0 )
+      args[0] = NEG_LONG( args[0] );
   }