diff --git a/kdc/headers.h b/kdc/headers.h
index 9e5ac48b1..f8157acc7 100644
--- a/kdc/headers.h
+++ b/kdc/headers.h
@@ -95,6 +95,7 @@
 #include <der.h>
 
 #include <heimntlm.h>
+#include <windc_plugin.h>
 
 #undef ALLOC
 #define ALLOC(X) ((X) = malloc(sizeof(*(X))))