diff --git a/config.h.cmake b/config.h.cmake
index d7e2b4dd6..7b3372f09 100644
--- a/config.h.cmake
+++ b/config.h.cmake
@@ -131,7 +131,7 @@
 #cmakedefine DEV_RANDOM "@DEV_RANDOM@"
 
 #cmakedefine USE_PAM 1
-#define KDM_PAM_SERVICE "kde"
+#cmakedefine KDM_PAM_SERVICE "@KDM_PAM_SERVICE@"
 
 #define USESHADOW 1
 #define HAVE_SHADOW 1
diff --git a/kdm/CMakeLists.txt b/kdm/CMakeLists.txt
index 73bcba446..0e7a32789 100644
--- a/kdm/CMakeLists.txt
+++ b/kdm/CMakeLists.txt
@@ -13,6 +13,10 @@
 # FIXME needs more checks (for kerberos, etc)
 # FIXME Xsession need some improvements
 
+if( NOT DEFINED KDM_PAM_SERVICE )
+  set( KDM_PAM_SERVICE "kde" CACHE INTERNAL "" )
+endif( )
+
 include( ConfigureChecks.cmake )
 
 add_subdirectory( backend )