diff --git a/man7/system_data_types.7 b/man7/system_data_types.7
index c621bfd2d..92e5ab4f1 100644
--- a/man7/system_data_types.7
+++ b/man7/system_data_types.7
@@ -147,6 +147,48 @@ Conforming to: C99 and later; POSIX.1-2001 and later.
 .IP
 See also:
 .BR fenv (3)
+.\"------------------------------------- float_t ----------------------/
+.TP
+.I float_t
+.IP
+Include:
+.IR <math.h> .
+.IP
+The implementation's most efficient floating type at least as wide as
+.IR float .
+Its type depends on the value of the macro
+.BR FLT_EVAL_METHOD ,
+defined in
+.IR <float.h> :
+.RS
+.TP
+0
+.I float_t
+is
+.IR float .
+.TP
+1
+.I float_t
+is
+.IR double .
+.TP
+2
+.I float_t
+is
+.IR "long double" .
+.IP
+For other values of
+.BR FLT_EVAL_METHOD ,
+the type of
+.I float_t
+is implementation-defined.
+.RE
+.IP
+Conforming to: C99 and later; POSIX.1-2001 and later.
+.IP
+See also the
+.I double_t
+type in this page.
 .\"------------------------------------- gid_t ------------------------/
 .TP
 .I gid_t