diff --git a/ChangeLog b/ChangeLog
index 70e9a00fc2..2a65383f12 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,8 @@
 2017-11-24  Joseph Myers  <joseph@codesourcery.com>
 
+	* math/gen-tgmath-tests.py (Type.init_types): Pass suffix argument
+	for combinations of long double with _Float64 and _Float64x.
+
 	* bits/libm-simd-decl-stubs.h (__DECL_SIMD_cosf16): New macro.
 	(__DECL_SIMD_cosf32): Likewise.
 	(__DECL_SIMD_cosf64): Likewise.
diff --git a/math/gen-tgmath-tests.py b/math/gen-tgmath-tests.py
index 88307a7841..55e9accb60 100755
--- a/math/gen-tgmath-tests.py
+++ b/math/gen-tgmath-tests.py
@@ -203,11 +203,11 @@ class Type(object):
         # Internal types represent the combination of long double with
         # _Float64 or _Float64x, for which the ordering depends on
         # whether long double has the same format as double.
-        Type.create_type('long_double_Float64', 'LDBL_MANT_DIG',
+        Type.create_type('long_double_Float64', None, 'LDBL_MANT_DIG',
                          complex_name='complex_long_double_Float64',
                          condition='defined HUGE_VAL_F64', order=(6, 7),
                          internal=True)
-        Type.create_type('long_double_Float64x', 'FLT64X_MANT_DIG',
+        Type.create_type('long_double_Float64x', None, 'FLT64X_MANT_DIG',
                          complex_name='complex_long_double_Float64x',
                          condition='defined HUGE_VAL_F64X', order=(7, 7),
                          internal=True)