diff --git a/doc/src/sgml/protocol.sgml b/doc/src/sgml/protocol.sgml
index 946d5634913..1a70685021d 100644
--- a/doc/src/sgml/protocol.sgml
+++ b/doc/src/sgml/protocol.sgml
@@ -2757,8 +2757,10 @@ psql "dbname=postgres replication=database" -c "IDENTIFY_SYSTEM;"
            <literal>-1</literal>), for <literal>lz4</literal> an integer
            between 1 and 12 (default <literal>0</literal> for fast compression
            mode), and for <literal>zstd</literal> an integer between
-           <literal>1</literal> and <literal>22</literal> (default
-           <literal>ZSTD_CLEVEL_DEFAULT</literal> or <literal>3</literal>).
+           <literal>ZSTD_minCLevel()</literal> (usually <literal>-131072</literal>)
+           and <literal>ZSTD_maxCLevel()</literal> (usually <literal>22</literal>),
+           (default <literal>ZSTD_CLEVEL_DEFAULT</literal> or
+           <literal>3</literal>).
           </para>
 
           <para>
diff --git a/src/common/compression.c b/src/common/compression.c
index e40ce98ef3a..0c6bb9177b9 100644
--- a/src/common/compression.c
+++ b/src/common/compression.c
@@ -324,8 +324,9 @@ validate_compress_specification(pg_compress_specification *spec)
 			default_level = 0;	/* fast mode */
 			break;
 		case PG_COMPRESSION_ZSTD:
-			max_level = 22;
 #ifdef USE_ZSTD
+			max_level = ZSTD_maxCLevel();
+			min_level = ZSTD_minCLevel();
 			default_level = ZSTD_CLEVEL_DEFAULT;
 #endif
 			break;