diff --git a/src/constants.c b/src/constants.c
index b5d7b8e4..4c890729 100644
--- a/src/constants.c
+++ b/src/constants.c
@@ -284,7 +284,9 @@ int PyXmlSec_ConstantsModule_Init(PyObject* package) {
     PYXMLSEC_ADD_NS_CONSTANT(Ns, "BASE");
     PYXMLSEC_ADD_NS_CONSTANT(DSigNs, "DS");
     PYXMLSEC_ADD_NS_CONSTANT(EncNs, "ENC");
+#ifndef XMLSEC_NO_XKMS
     PYXMLSEC_ADD_NS_CONSTANT(XkmsNs, "XKMS");
+#endif
     PYXMLSEC_ADD_NS_CONSTANT(XPathNs, "XPATH");
     PYXMLSEC_ADD_NS_CONSTANT(XPath2Ns, "XPATH2");
     PYXMLSEC_ADD_NS_CONSTANT(XPointerNs, "XPOINTER");
diff --git a/src/platform.h b/src/platform.h
index bde45cee..eae902b9 100644
--- a/src/platform.h
+++ b/src/platform.h
@@ -21,6 +21,12 @@
 
 #define XMLSEC_VERSION_HEX ((XMLSEC_VERSION_MAJOR << 8) | (XMLSEC_VERSION_MINOR << 4) | (XMLSEC_VERSION_SUBMINOR))
 
+// XKMS support was removed in version 1.2.21
+// https://mail.gnome.org/archives/commits-list/2015-February/msg10555.html
+#if  XMLSEC_VERSION_HEX > 0x134
+#define XMLSEC_NO_XKMS 1
+#endif
+
 #define XSTR(c) (const xmlChar*)(c)
 
 #if PY_VERSION_HEX < 0x02050000 && !defined(PY_SSIZE_T_MIN)