diff --git a/man3/ecvt.3 b/man3/ecvt.3
index 9b2d2055d..851c4d25c 100644
--- a/man3/ecvt.3
+++ b/man3/ecvt.3
@@ -47,23 +47,18 @@ Feature Test Macro Requirements for glibc (see
 .PP
 .BR ecvt (),
 .BR fcvt ():
-.ad l
-.RS 4
-.PD 0
-.TP 4
-Since glibc 2.12:
 .nf
-(_XOPEN_SOURCE\ >=\ 500) ! (_POSIX_C_SOURCE\ >=\ 200112L)
-    || /* Glibc since 2.19: */ _DEFAULT_SOURCE
-    || /* Glibc <= 2.19: */ _SVID_SOURCE
+    Since glibc 2.17
+        (_XOPEN_SOURCE >= 500 && ! (_POSIX_C_SOURCE >= 200809L))
+            || /* Glibc >= 2.20 */ _DEFAULT_SOURCE
+            || /* Glibc <= 2.19 */ _SVID_SOURCE
+    Glibc versions 2.12 to 2.16:
+        (_XOPEN_SOURCE >= 500 && ! (_POSIX_C_SOURCE >= 200112L))
+            || _SVID_SOURCE
+    Before glibc 2.12:
+        _SVID_SOURCE || _XOPEN_SOURCE\ >=\ 500
+.\"        || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED
 .fi
-.TP 4
-Before glibc 2.12:
-_SVID_SOURCE || _XOPEN_SOURCE\ >=\ 500
-.\"    || _XOPEN_SOURCE\ &&\ _XOPEN_SOURCE_EXTENDED
-.PD
-.RE
-.ad b
 .SH DESCRIPTION
 The
 .BR ecvt ()
diff --git a/man3/gcvt.3 b/man3/gcvt.3
index 973beedaf..d28928a9f 100644
--- a/man3/gcvt.3
+++ b/man3/gcvt.3
@@ -43,23 +43,18 @@ Feature Test Macro Requirements for glibc (see
 .RE
 .PP
 .BR gcvt ():
-.ad l
-.PD 0
-.RS 4
-.TP 4
-Since glibc 2.12:
 .nf
-(_XOPEN_SOURCE\ >=\ 500) ! (_POSIX_C_SOURCE\ >=\ 200112L)
-    || /* Glibc since 2.19: */ _DEFAULT_SOURCE
-    || /* Glibc <= 2.19: */ _SVID_SOURCE
+    Since glibc 2.17
+        (_XOPEN_SOURCE >= 500 && ! (_POSIX_C_SOURCE >= 200809L))
+            || /* Glibc >= 2.20 */ _DEFAULT_SOURCE
+            || /* Glibc <= 2.19 */ _SVID_SOURCE
+    Glibc versions 2.12 to 2.16:
+        (_XOPEN_SOURCE >= 500 && ! (_POSIX_C_SOURCE >= 200112L))
+            || _SVID_SOURCE
+    Before glibc 2.12:
+        _SVID_SOURCE || _XOPEN_SOURCE\ >=\ 500
+.\"        || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED
 .fi
-.TP 4
-Before glibc 2.12:
-_SVID_SOURCE || _XOPEN_SOURCE\ >=\ 500
-.\"    || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED
-.RE
-.PD
-.ad b
 .SH DESCRIPTION
 The
 .BR gcvt ()