diff --git a/lib/cluster/crmcluster_private.h b/lib/cluster/crmcluster_private.h
index ef1d54f628..4d06f99cdc 100644
--- a/lib/cluster/crmcluster_private.h
+++ b/lib/cluster/crmcluster_private.h
@@ -1,63 +1,67 @@
 /*
  * Copyright 2020-2024 the Pacemaker project contributors
  *
  * The version control history for this file may have further details.
  *
  * This source code is licensed under the GNU Lesser General Public License
  * version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY.
  */
 
 #ifndef PCMK__CRMCLUSTER_PRIVATE__H
 #  define PCMK__CRMCLUSTER_PRIVATE__H
 
 /* This header is for the sole use of libcrmcluster, so that functions can be
  * declared with G_GNUC_INTERNAL for efficiency.
  */
 
 #include <stdint.h>                // uint32_t, uint64_t
 
 #include <glib.h>                  // G_GNUC_INTERNAL, gboolean
 #include <libxml/tree.h>           // xmlNode
 
 #if SUPPORT_COROSYNC
 #include <corosync/cpg.h>          // cpg_handle_t
 #endif  // SUPPORT_COROSYNC
 
 #include <crm/cluster.h>           // crm_node_t
 
+#if SUPPORT_COROSYNC
+
 G_GNUC_INTERNAL
 bool pcmk__corosync_is_active(void);
 
 G_GNUC_INTERNAL
 bool pcmk__corosync_has_nodelist(void);
 
 G_GNUC_INTERNAL
 char *pcmk__corosync_uuid(const crm_node_t *peer);
 
 G_GNUC_INTERNAL
 char *pcmk__corosync_name(uint64_t /*cmap_handle_t */ cmap_handle,
                           uint32_t nodeid);
 
 G_GNUC_INTERNAL
 int pcmk__corosync_connect(pcmk_cluster_t *cluster);
 
 G_GNUC_INTERNAL
 void pcmk__corosync_disconnect(pcmk_cluster_t *cluster);
 
 G_GNUC_INTERNAL
 bool pcmk__corosync_is_peer_active(const crm_node_t *node);
 
 G_GNUC_INTERNAL
 int pcmk__cpg_connect(pcmk_cluster_t *cluster);
 
 G_GNUC_INTERNAL
 void pcmk__cpg_disconnect(pcmk_cluster_t *cluster);
 
 G_GNUC_INTERNAL
 uint32_t pcmk__cpg_local_nodeid(cpg_handle_t handle);
 
 G_GNUC_INTERNAL
 bool pcmk__cpg_send_xml(const xmlNode *msg, const crm_node_t *node,
                         enum crm_ais_msg_types dest);
 
+#endif  // SUPPORT_COROSYNC
+
 #endif  // PCMK__CRMCLUSTER_PRIVATE__H