diff --git a/lib/libspl/include/umem.h b/lib/libspl/include/umem.h
index 3e19aff9ec..0ed55ae5af 100644
--- a/lib/libspl/include/umem.h
+++ b/lib/libspl/include/umem.h
@@ -42,9 +42,22 @@
 extern "C" {
 #endif
 
+typedef void vmem_t;
+
+/*
+ * Flags for umem_alloc/umem_free
+ */
 #define UMEM_DEFAULT		0x0000  /* normal -- may fail */
 #define UMEM_NOFAIL		0x0100  /* Never fails */
 
+/*
+ * Flags for umem_cache_create()
+ */
+#define UMC_NOTOUCH		0x00010000
+#define UMC_NODEBUG		0x00020000
+#define UMC_NOMAGAZINE		0x00040000
+#define UMC_NOHASH		0x00080000
+
 #define UMEM_CACHE_NAMELEN	31
 
 typedef int umem_nofail_callback_t(void);