diff --git a/intl/lwbrk/nsJISx4051LineBreaker.cpp b/intl/lwbrk/nsJISx4051LineBreaker.cpp
index 1b262fa2cb..fe4191a5f1 100644
--- a/intl/lwbrk/nsJISx4051LineBreaker.cpp
+++ b/intl/lwbrk/nsJISx4051LineBreaker.cpp
@@ -553,10 +553,8 @@ GetClass(uint32_t u)
     /* ZWJ = 42,                          [ZWJ]*/ CLASS_CHARACTER
   };
 
-#if ENABLE_INTL_API
   static_assert(U_LB_COUNT == mozilla::ArrayLength(sUnicodeLineBreakToClass),
                 "Gecko vs ICU LineBreak class mismatch");
-#endif
 
   auto cls = mozilla::unicode::GetLineBreakClass(u);
   MOZ_ASSERT(cls < mozilla::ArrayLength(sUnicodeLineBreakToClass));