--- src/autofit/aflatin.c
+++ src/autofit/aflatin.c
@@ -3711,11 +3711,13 @@
         /* We also check that the y minimum of the 'other' contour */
         /* is below the high contour to avoid potential false hits */
         /* with contours enclosed in the high one.                 */
+        if (max_y != FT_LONG_MIN) {
         distance = SUB_LONG( high_min_y, max_y );
         if ( distance < 64           &&
              distance < min_distance &&
              min_y < high_min_y      )
           min_distance = distance;
+        }
       }
 
       adjustment_amount = 64 - min_distance;
--- src/truetype/ttgxvar.c
+++ src/truetype/ttgxvar.c
@@ -1217,7 +1217,7 @@
       per_region_size *= 2;
     }
 
-    bytes = varData->deltaSet + per_region_size * innerIndex;
+    bytes = varData->deltaSet ? varData->deltaSet + per_region_size * innerIndex : NULL;
 
     /* outer loop steps through master designs to be blended */
     for ( master = 0; master < varData->regionIdxCount; master++ )