--- a/gfx/thebes/gfxScriptItemizer.cpp
+++ b/gfx/thebes/gfxScriptItemizer.cpp
@@ -170,17 +170,17 @@ gfxScriptItemizer::Next(uint32_t& aRunSt
              * if it's an open character, push it onto the stack.
              * if it's a close character, find the matching open on the
              * stack, and use that script code. Any non-matching open
              * characters above it on the stack will be popped.
              *
              * We only do this if the script is COMMON; for chars with
              * specific script assignments, we just use them as-is.
              */
-            GetGeneralCategory(ch);
+            gc = GetGeneralCategory(ch);
             if (gc == HB_UNICODE_GENERAL_CATEGORY_OPEN_PUNCTUATION) {
                 uint32_t endPairChar = mozilla::unicode::GetMirroredChar(ch);
                 if (endPairChar != ch) {
                     push(endPairChar, scriptCode);
                 }
             } else if (gc == HB_UNICODE_GENERAL_CATEGORY_CLOSE_PUNCTUATION &&
                 HasMirroredChar(ch))
             {