diff --git a/doc/src/sgml/backup.sgml b/doc/src/sgml/backup.sgml
index b3468eea3cb..91da3c26ba0 100644
--- a/doc/src/sgml/backup.sgml
+++ b/doc/src/sgml/backup.sgml
@@ -892,7 +892,11 @@ test ! -f /mnt/server/archivedir/00000001000000A900000065 && cp pg_wal/0
     only the incremental backup itself but also all earlier backups that
     are required to supply the blocks omitted from the incremental backup.
     See <xref linkend="app-pgcombinebackup"/> for further information about
-    this requirement.
+    this requirement. Note that there are restrictions on the use of
+    <literal>pg_combinebackup</literal> when the checksum status of the
+    cluster has been changed; see
+    <link linkend="app-pgcombinebackup-limitations">pg_combinebackup
+    limitations</link>.
    </para>
 
    <para>
diff --git a/doc/src/sgml/ref/pg_combinebackup.sgml b/doc/src/sgml/ref/pg_combinebackup.sgml
index 96df3d81f15..d1f70ba2358 100644
--- a/doc/src/sgml/ref/pg_combinebackup.sgml
+++ b/doc/src/sgml/ref/pg_combinebackup.sgml
@@ -261,6 +261,26 @@ PostgreSQL documentation
 
  </refsect1>
 
+ <refsect1 id="app-pgcombinebackup-limitations">
+  <title>Limitations</title>
+
+  <para>
+   <literal>pg_combinebackup</literal> does not recompute page checksums when
+   writing the output directory. Therefore, if any of the backups used for
+   reconstruction were taken with checksums disabled, but the final backup was
+   taken with checksums enabled, the resulting directory may contain pages
+   with invalid checksums.
+  </para>
+
+  <para>
+   To avoid this problem, taking a new full backup after changing the checksum
+   state of the cluster using <xref linkend="app-pgchecksums "/> is
+   recommended. Otherwise, you can disable and then optionally reenable
+   checksums on the directory produced by <literal>pg_combinebackup</literal>
+   in order to correct the problem.
+  </para>
+ </refsect1>
+
  <refsect1>
   <title>Environment</title>
 
diff --git a/src/bin/pg_combinebackup/pg_combinebackup.c b/src/bin/pg_combinebackup/pg_combinebackup.c
index 4958372653b..232ba5b0697 100644
--- a/src/bin/pg_combinebackup/pg_combinebackup.c
+++ b/src/bin/pg_combinebackup/pg_combinebackup.c
@@ -583,6 +583,8 @@ check_control_files(int n_backups, char **backup_dirs)
 {
 	int			i;
 	uint64		system_identifier = 0;	/* placate compiler */
+	uint32		data_checksum_version = 0;	/* placate compiler */
+	bool		data_checksum_mismatch = false;
 
 	/* Try to read each control file in turn, last to first. */
 	for (i = n_backups - 1; i >= 0; --i)
@@ -612,6 +614,16 @@ check_control_files(int n_backups, char **backup_dirs)
 					 controlpath, (unsigned long long) system_identifier,
 					 (unsigned long long) control_file->system_identifier);
 
+		/*
+		 * Detect checksum mismatches, but only if the last backup in the
+		 * chain has checksums enabled.
+		 */
+		if (i == n_backups - 1)
+			data_checksum_version = control_file->data_checksum_version;
+		else if (data_checksum_version != 0 &&
+				 data_checksum_version != control_file->data_checksum_version)
+			data_checksum_mismatch = true;
+
 		/* Release memory. */
 		pfree(control_file);
 		pfree(controlpath);
@@ -624,6 +636,16 @@ check_control_files(int n_backups, char **backup_dirs)
 	pg_log_debug("system identifier is %llu",
 				 (unsigned long long) system_identifier);
 
+	/*
+	 * Warn the user if not all backups are in the same state with regards to
+	 * checksums.
+	 */
+	if (data_checksum_mismatch)
+	{
+		pg_log_warning("only some backups have checksums enabled");
+		pg_log_warning_hint("disable, and optionally reenable, checksums on the output directory to avoid failures");
+	}
+
 	return system_identifier;
 }