diff --git a/Xext/sync.c b/Xext/sync.c
index 4c4835929..a8db0ec22 100644
--- a/Xext/sync.c
+++ b/Xext/sync.c
@@ -919,7 +919,7 @@ SyncCreate(ClientPtr client, XID id, unsigned char type)
 int
 SyncCreateFenceFromFD(ClientPtr client, DrawablePtr pDraw, XID id, int fd, BOOL initially_triggered)
 {
-#if HAVE_XSHMFENCE
+#ifdef HAVE_XSHMFENCE
     SyncFence  *pFence;
     int         status;
 
@@ -945,7 +945,7 @@ SyncCreateFenceFromFD(ClientPtr client, DrawablePtr pDraw, XID id, int fd, BOOL
 int
 SyncFDFromFence(ClientPtr client, DrawablePtr pDraw, SyncFence *pFence)
 {
-#if HAVE_XSHMFENCE
+#ifdef HAVE_XSHMFENCE
     return miSyncFDFromFence(pDraw, pFence);
 #else
     return BadImplementation;
diff --git a/include/meson.build b/include/meson.build
index 2f8882803..ef3163d1f 100644
--- a/include/meson.build
+++ b/include/meson.build
@@ -62,7 +62,7 @@ conf_data.set('CONFIG_WSCONS', host_machine.system() == 'openbsd')
 # that just uses whatever directory works?
 conf_data.set_quoted('SHMDIR', '/tmp')
 
-conf_data.set('XSHMFENCE', xshmfence_dep.found())
+conf_data.set('HAVE_XSHMFENCE', xshmfence_dep.found())
 conf_data.set('WITH_LIBDRM', libdrm_dep.found())
 conf_data.set('GLAMOR_HAS_DRM_NAME_FROM_FD_2',
               dependency('libdrm', version: '>= 2.4.74', required: false).found())