diff --git a/include/math.h b/include/math.h
index fe3ed13..7ee291f 100644
--- a/include/math.h
+++ b/include/math.h
@@ -2,7 +2,6 @@
 
 #ifdef _ISOMAC
 # undef NO_LONG_DOUBLE
-# undef _Mlong_double_
 #endif
 
 #include <math/math.h>
diff --git a/math/Makefile b/math/Makefile
index 1feb425..b2bd3d3 100644
--- a/math/Makefile
+++ b/math/Makefile
@@ -561,10 +561,8 @@ math-CPPFLAGS += -D__NO_MATH_INLINES -D__LIBC_INTERNAL_MATH_INLINES
 ifneq ($(long-double-fcts),yes)
 # The `double' and `long double' types are the same on this machine.
 # We won't compile the `long double' code at all.  Tell the `double' code
-# to define aliases for the `FUNCl' names.  To avoid type conflicts in
-# defining those aliases, tell <math.h> to declare the `FUNCl' names with
-# `double' instead of `long double'.
-math-CPPFLAGS += -DNO_LONG_DOUBLE -D_Mlong_double_=double
+# to define aliases for the `FUNCl' names.
+math-CPPFLAGS += -DNO_LONG_DOUBLE
 endif
 
 # These files quiet sNaNs in a way that is optimized away without
diff --git a/math/complex.h b/math/complex.h
index 1ae4ec2..9a6cc3e 100644
--- a/math/complex.h
+++ b/math/complex.h
@@ -83,10 +83,7 @@ __BEGIN_DECLS
 #undef	__MATH_PRECNAME
 
 /* Now the float versions.  */
-#ifndef _Mfloat_
-# define _Mfloat_		float
-#endif
-#define _Mdouble_ 		_Mfloat_
+#define _Mdouble_ 		float
 #define __MATH_PRECNAME(name)	name##f
 #include <bits/cmathcalls.h>
 #undef	_Mdouble_
@@ -94,15 +91,12 @@ __BEGIN_DECLS
 
 #if (__HAVE_DISTINCT_FLOAT128 || (__HAVE_FLOAT128 && !defined _LIBC)) \
      && __GLIBC_USE (IEC_60559_TYPES_EXT)
-# ifndef _Mfloat128_
-#  define _Mfloat128_		_Float128
-# endif
 /* GCC < 7 requires extra convincing to expose a complex float128 type.  */
 # ifdef __CFLOAT128
 #  undef _Mdouble_complex_
 #  define _Mdouble_complex_	__CFLOAT128
 # endif
-# define _Mdouble_		_Mfloat128_
+# define _Mdouble_		_Float128
 # define __MATH_PRECNAME(name)	name##f128
 # include <bits/cmathcalls.h>
 # undef _Mdouble_
@@ -120,10 +114,7 @@ __BEGIN_DECLS
   extern type __REDIRECT_NTH(__MATH_PRECNAME(function), args, function)
 # endif
 
-# ifndef _Mlong_double_
-#  define _Mlong_double_	long double
-# endif
-# define _Mdouble_ 		_Mlong_double_
+# define _Mdouble_ 		long double
 # define __MATH_PRECNAME(name)	name##l
 # include <bits/cmathcalls.h>
 #endif
diff --git a/math/math.h b/math/math.h
index 5683ac9..88fd4bc 100644
--- a/math/math.h
+++ b/math/math.h
@@ -299,10 +299,7 @@ enum
 /* Include the file of declarations again, this time using `float'
    instead of `double' and appending f to each function name.  */
 
-# ifndef _Mfloat_
-#  define _Mfloat_		float
-# endif
-# define _Mdouble_		_Mfloat_
+# define _Mdouble_		float
 # define __MATH_PRECNAME(name,r) name##f##r
 # define __MATH_DECLARING_DOUBLE  0
 # define __MATH_DECLARING_FLOATN  0
@@ -344,10 +341,7 @@ extern long double __REDIRECT_NTH (nexttowardl,
 /* Include the file of declarations again, this time using `long double'
    instead of `double' and appending l to each function name.  */
 
-#  ifndef _Mlong_double_
-#   define _Mlong_double_	long double
-#  endif
-#  define _Mdouble_		_Mlong_double_
+#  define _Mdouble_		long double
 #  define __MATH_PRECNAME(name,r) name##l##r
 #  define __MATH_DECLARING_DOUBLE  0
 #  define __MATH_DECLARING_FLOATN  0
@@ -367,10 +361,7 @@ extern long double __REDIRECT_NTH (nexttowardl,
    types.  */
 
 #if __HAVE_DISTINCT_FLOAT16 || (__HAVE_FLOAT16 && !defined _LIBC)
-# ifndef _Mfloat16_
-#  define _Mfloat16_		_Float16
-# endif
-# define _Mdouble_		_Mfloat16_
+# define _Mdouble_		_Float16
 # define __MATH_PRECNAME(name,r) name##f16##r
 # define __MATH_DECLARING_DOUBLE  0
 # define __MATH_DECLARING_FLOATN  1
@@ -387,10 +378,7 @@ extern long double __REDIRECT_NTH (nexttowardl,
 #endif /* __HAVE_DISTINCT_FLOAT16 || (__HAVE_FLOAT16 && !_LIBC).  */
 
 #if __HAVE_DISTINCT_FLOAT32 || (__HAVE_FLOAT32 && !defined _LIBC)
-# ifndef _Mfloat32_
-#  define _Mfloat32_		_Float32
-# endif
-# define _Mdouble_		_Mfloat32_
+# define _Mdouble_		_Float32
 # define __MATH_PRECNAME(name,r) name##f32##r
 # define __MATH_DECLARING_DOUBLE  0
 # define __MATH_DECLARING_FLOATN  1
@@ -407,10 +395,7 @@ extern long double __REDIRECT_NTH (nexttowardl,
 #endif /* __HAVE_DISTINCT_FLOAT32 || (__HAVE_FLOAT32 && !_LIBC).  */
 
 #if __HAVE_DISTINCT_FLOAT64 || (__HAVE_FLOAT64 && !defined _LIBC)
-# ifndef _Mfloat64_
-#  define _Mfloat64_		_Float64
-# endif
-# define _Mdouble_		_Mfloat64_
+# define _Mdouble_		_Float64
 # define __MATH_PRECNAME(name,r) name##f64##r
 # define __MATH_DECLARING_DOUBLE  0
 # define __MATH_DECLARING_FLOATN  1
@@ -427,10 +412,7 @@ extern long double __REDIRECT_NTH (nexttowardl,
 #endif /* __HAVE_DISTINCT_FLOAT64 || (__HAVE_FLOAT64 && !_LIBC).  */
 
 #if __HAVE_DISTINCT_FLOAT128 || (__HAVE_FLOAT128 && !defined _LIBC)
-# ifndef _Mfloat128_
-#  define _Mfloat128_		_Float128
-# endif
-# define _Mdouble_		_Mfloat128_
+# define _Mdouble_		_Float128
 # define __MATH_PRECNAME(name,r) name##f128##r
 # define __MATH_DECLARING_DOUBLE  0
 # define __MATH_DECLARING_FLOATN  1
@@ -447,10 +429,7 @@ extern long double __REDIRECT_NTH (nexttowardl,
 #endif /* __HAVE_DISTINCT_FLOAT128 || (__HAVE_FLOAT128 && !_LIBC).  */
 
 #if __HAVE_DISTINCT_FLOAT32X || (__HAVE_FLOAT32X && !defined _LIBC)
-# ifndef _Mfloat32x_
-#  define _Mfloat32x_		_Float32x
-# endif
-# define _Mdouble_		_Mfloat32x_
+# define _Mdouble_		_Float32x
 # define __MATH_PRECNAME(name,r) name##f32x##r
 # define __MATH_DECLARING_DOUBLE  0
 # define __MATH_DECLARING_FLOATN  1
@@ -467,10 +446,7 @@ extern long double __REDIRECT_NTH (nexttowardl,
 #endif /* __HAVE_DISTINCT_FLOAT32X || (__HAVE_FLOAT32X && !_LIBC).  */
 
 #if __HAVE_DISTINCT_FLOAT64X || (__HAVE_FLOAT64X && !defined _LIBC)
-# ifndef _Mfloat64x_
-#  define _Mfloat64x_		_Float64x
-# endif
-# define _Mdouble_		_Mfloat64x_
+# define _Mdouble_		_Float64x
 # define __MATH_PRECNAME(name,r) name##f64x##r
 # define __MATH_DECLARING_DOUBLE  0
 # define __MATH_DECLARING_FLOATN  1
@@ -487,10 +463,7 @@ extern long double __REDIRECT_NTH (nexttowardl,
 #endif /* __HAVE_DISTINCT_FLOAT64X || (__HAVE_FLOAT64X && !_LIBC).  */
 
 #if __HAVE_DISTINCT_FLOAT128X || (__HAVE_FLOAT128X && !defined _LIBC)
-# ifndef _Mfloat128x_
-#  define _Mfloat128x_		_Float128x
-# endif
-# define _Mdouble_		_Mfloat128x_
+# define _Mdouble_		_Float128x
 # define __MATH_PRECNAME(name,r) name##f128x##r
 # define __MATH_DECLARING_DOUBLE  0
 # define __MATH_DECLARING_FLOATN  1
diff --git a/math/test-signgam-finite-c99.c b/math/test-signgam-finite-c99.c
index 07fdcda..cfe9df0 100644
--- a/math/test-signgam-finite-c99.c
+++ b/math/test-signgam-finite-c99.c
@@ -19,7 +19,6 @@
 #undef _LIBC
 #undef __LIBC_INTERNAL_MATH_INLINES
 #undef _GNU_SOURCE
-#undef _Mlong_double_
 
 #include <math.h>
 #include <stdio.h>
