diff --git a/src/core/cff_parser.js b/src/core/cff_parser.js
index a6c7bae35..3f4b6865d 100644
--- a/src/core/cff_parser.js
+++ b/src/core/cff_parser.js
@@ -640,7 +640,9 @@ const CFFParser = (function CFFParserClosure() {
             } else if (stackSize > 1) {
               warn("Found too many parameters for stack-clearing command");
             }
-            if (stackSize > 0 && stack[stackSize - 1] >= 0) {
+            if (stackSize > 0) {
+              // Width can be any number since its the difference
+              // from nominalWidthX.
               state.width = stack[stackSize - 1];
             }
           }