diff --git a/libcxxabi/src/demangle/ItaniumDemangle.h b/libcxxabi/src/demangle/ItaniumDemangle.h
index 4122781beb599..b9d17060c04f9 100644
--- a/libcxxabi/src/demangle/ItaniumDemangle.h
+++ b/libcxxabi/src/demangle/ItaniumDemangle.h
@@ -5741,14 +5741,16 @@ struct FloatData<double>
 template <>
 struct FloatData<long double>
 {
-#if defined(__mips__) && defined(__mips_n64) || defined(__aarch64__) || \
-    defined(__wasm__) || defined(__riscv) || defined(__loongarch__) || \
-    defined(__ve__)
-    static const size_t mangled_size = 32;
-#elif defined(__arm__) || defined(__mips__) || defined(__hexagon__)
-    static const size_t mangled_size = 16;
+#if __LDBL_MANT_DIG__ == 113
+  static const size_t mangled_size = 32;
+#elif __LDBL_MANT_DIG__ == 53 || defined(_MSC_VER)
+  // MSVC doesn't define __LDBL_MANT_DIG__, but it has long double equal to
+  // regular double on all current architectures.
+  static const size_t mangled_size = 16;
+#elif __LDBL_MANT_DIG__ == 64
+  static const size_t mangled_size = 20;
 #else
-    static const size_t mangled_size = 20;  // May need to be adjusted to 16 or 24 on other platforms
+#error Unknown size for __LDBL_MANT_DIG__
 #endif
     // `-0x1.ffffffffffffffffffffffffffffp+16383` + 'L' + '\0' == 42 bytes.
     // 28 'f's * 4 bits == 112 bits, which is the number of mantissa bits.
diff --git a/libcxxabi/test/test_demangle.pass.cpp b/libcxxabi/test/test_demangle.pass.cpp
index e9c74f70a094b..abaa787f5432b 100644
--- a/libcxxabi/test/test_demangle.pass.cpp
+++ b/libcxxabi/test/test_demangle.pass.cpp
@@ -13,10 +13,6 @@
 // dd8b266ef.
 // UNSUPPORTED: using-built-library-before-llvm-20
 
-// Android's long double on x86[-64] is (64/128)-bits instead of Linux's usual
-// 80-bit format, and this demangling test is failing on it.
-// XFAIL: LIBCXX-ANDROID-FIXME && target={{i686|x86_64}}-{{.+}}-android{{.*}}
-
 // XFAIL: win32-broken-printf-a-precision
 
 #include "support/timer.h"