diff --git a/doc/src/sgml/ref/pg_basebackup.sgml b/doc/src/sgml/ref/pg_basebackup.sgml
index 4d679d0a05..03615da480 100644
--- a/doc/src/sgml/ref/pg_basebackup.sgml
+++ b/doc/src/sgml/ref/pg_basebackup.sgml
@@ -364,7 +364,7 @@ PostgreSQL documentation
       <listitem>
        <para>
         Enables gzip compression of tar file output, and specifies the
-        compression level (1 through 9, 9 being best
+        compression level (0 through 9, 0 being no compression and 9 being best
         compression). Compression is only available when using the tar
         format.
        </para>
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index ec69682d20..ed41db8e6e 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -2073,7 +2073,7 @@ main(int argc, char **argv)
 				break;
 			case 'Z':
 				compresslevel = atoi(optarg);
-				if (compresslevel <= 0 || compresslevel > 9)
+				if (compresslevel < 0 || compresslevel > 9)
 				{
 					fprintf(stderr, _("%s: invalid compression level \"%s\"\n"),
 							progname, optarg);