diff --git a/doc/src/sgml/ref/repack.sgml b/doc/src/sgml/ref/repack.sgml
index d9c7c9e6b95..3c83f529298 100644
--- a/doc/src/sgml/ref/repack.sgml
+++ b/doc/src/sgml/ref/repack.sgml
@@ -285,6 +285,12 @@ REPACK [ ( <replaceable class="parameter">option</replaceable> [, ...] ) ] USING
         </para>
        </listitem>
 
+       <listitem>
+        <para>
+          The table's access method is not <literal>heap</literal>.
+        </para>
+       </listitem>
+
        <listitem>
         <para>
          <command>REPACK</command> is executed inside a transaction block.
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 89aa038d23d..7cba8bece9c 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -888,6 +888,20 @@ check_concurrent_repack_requirements(Relation rel, Oid *ident_idx_p)
 				errdetail("%s requires \"wal_level\" to be set to \"replica\" or higher.",
 						  "REPACK (CONCURRENTLY)"));
 
+	/*
+	 * A table AM that doesn't support logical decoding would cause REPACK
+	 * (CONCURRENTLY) to silently lose the changes made during the rewrite.
+	 * Nothing in TableAmRoutine tells us whether it does, so for now restrict
+	 * to heap. Check the routine rather than the AM OID, so that an AM
+	 * reusing the heap handler still works.
+	 */
+	if (rel->rd_tableam != GetHeapamTableAmRoutine())
+		ereport(ERROR,
+				errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				errmsg("cannot execute %s on relation \"%s\"",
+					   "REPACK (CONCURRENTLY)", RelationGetRelationName(rel)),
+				errdetail("This operation is only supported for the \"heap\" access method."));
+
 	/* Data changes in system relations are not logically decoded. */
 	if (IsCatalogRelation(rel))
 		ereport(ERROR,