diff --git a/chapter01/changelog.xml b/chapter01/changelog.xml
index f724ac916..047a1d56f 100644
--- a/chapter01/changelog.xml
+++ b/chapter01/changelog.xml
@@ -42,6 +42,15 @@
     <listitem revision="sysv"> or <listitem revision="systemd"> as
     appropriate for the entry or if needed the entire day's listitem.
     -->
+    <listitem>
+      <para>2021-07-15</para>
+      <itemizedlist>
+        <listitem>
+          <para>[bdubbs] - Remove modifications to m4 that are no longer needed.</para>
+        </listitem>
+      </itemizedlist>
+    </listitem>
+
     <listitem>
       <para>2021-07-08</para>
       <itemizedlist>
diff --git a/chapter06/m4.xml b/chapter06/m4.xml
index 7a28a08cc..91e0a9ea2 100644
--- a/chapter06/m4.xml
+++ b/chapter06/m4.xml
@@ -42,12 +42,12 @@
 
   <sect2 role="installation">
     <title>Installation of M4</title>
-
+<!--
     <para>First, make some fixes introduced by glibc-2.28:</para>
 
 <screen><userinput remap="pre">sed -i 's/IO_ftrylockfile/IO_EOF_SEEN/' lib/*.c
 echo "#define _IO_IN_BACKUP 0x100" >> lib/stdio-impl.h</userinput></screen>
-
+-->
     <para>Prepare M4 for compilation:</para>
 
 <screen><userinput remap="configure">./configure --prefix=/usr   \
diff --git a/chapter08/m4.xml b/chapter08/m4.xml
index b8d57fba0..13b032a25 100644
--- a/chapter08/m4.xml
+++ b/chapter08/m4.xml
@@ -39,12 +39,12 @@
 
   <sect2 role="installation">
     <title>Installation of M4</title>
-
+<!--
     <para>First, make some fixes required by glibc-2.28 and later:</para>
 
 <screen><userinput remap="pre">sed -i 's/IO_ftrylockfile/IO_EOF_SEEN/' lib/*.c
 echo "#define _IO_IN_BACKUP 0x100" >> lib/stdio-impl.h</userinput></screen>
-
+-->
     <para>Prepare M4 for compilation:</para>
 
 <screen><userinput remap="configure">./configure --prefix=/usr</userinput></screen>