diff --git a/libc/test/src/__support/FPUtil/fpbits_test.cpp b/libc/test/src/__support/FPUtil/fpbits_test.cpp
--- a/libc/test/src/__support/FPUtil/fpbits_test.cpp
+++ b/libc/test/src/__support/FPUtil/fpbits_test.cpp
@@ -200,6 +200,7 @@
   if constexpr (sizeof(long double) == sizeof(double))
     return; // The tests for the "double" type cover for this case.
 
+  using UIntType = FPBits<long double>::UIntType;
   EXPECT_STREQ(FPBits<long double>::inf().str().c_str(), "(+Infinity)");
   EXPECT_STREQ(FPBits<long double>::neg_inf().str().c_str(), "(-Infinity)");
   EXPECT_STREQ(