diff --git a/sys/dev/efidev/efidev.c b/sys/dev/efidev/efidev.c
--- a/sys/dev/efidev/efidev.c
+++ b/sys/dev/efidev/efidev.c
@@ -52,12 +52,13 @@
 	switch (cmd) {
 	case EFIIOC_GET_TABLE:
 	{
-		struct efi_get_table_ioc *egtioc =
-		    (struct efi_get_table_ioc *)addr;
+		struct efi_get_table_ioctl *egtioc =
+		    (struct efi_get_table_ioctl *)addr;
 		void *buf = NULL;
 
-		error = efi_copy_table((efi_guid_t *)&egtioc->uuid, egtioc->buf ? &buf : NULL,
-		    egtioc->buf_len, &egtioc->table_len);
+		error = efi_copy_table(&egtioc->guid,
+		    egtioc->buf != NULL ? &buf : NULL, egtioc->buf_len,
+		    &egtioc->table_len);
 
 		if (error != 0 || egtioc->buf == NULL)
 			break;
@@ -89,7 +90,7 @@
 	}
 	case EFIIOC_GET_WAKETIME:
 	{
-		struct efi_waketime_ioc *wt = (struct efi_waketime_ioc *)addr;
+		struct efi_waketime_ioctl *wt = (struct efi_waketime_ioctl *)addr;
 
 		error = efi_get_waketime(&wt->enabled, &wt->pending,
 		    &wt->waketime);
@@ -97,14 +98,14 @@
 	}
 	case EFIIOC_SET_WAKETIME:
 	{
-		struct efi_waketime_ioc *wt = (struct efi_waketime_ioc *)addr;
+		struct efi_waketime_ioctl *wt = (struct efi_waketime_ioctl *)addr;
 
 		error = efi_set_waketime(wt->enabled, &wt->waketime);
 		break;
 	}
 	case EFIIOC_VAR_GET:
 	{
-		struct efi_var_ioc *ev = (struct efi_var_ioc *)addr;
+		struct efi_var_ioctl *ev = (struct efi_var_ioctl *)addr;
 		void *data;
 		efi_char *name;
 
@@ -140,7 +141,7 @@
 	}
 	case EFIIOC_VAR_NEXT:
 	{
-		struct efi_var_ioc *ev = (struct efi_var_ioc *)addr;
+		struct efi_var_ioctl *ev = (struct efi_var_ioctl *)addr;
 		efi_char *name;
 
 		name = malloc(ev->namesize, M_TEMP, M_WAITOK);
@@ -162,7 +163,7 @@
 	}
 	case EFIIOC_VAR_SET:
 	{
-		struct efi_var_ioc *ev = (struct efi_var_ioc *)addr;
+		struct efi_var_ioctl *ev = (struct efi_var_ioctl *)addr;
 		void *data = NULL;
 		efi_char *name;
 
diff --git a/sys/dev/efidev/efirt.c b/sys/dev/efidev/efirt.c
--- a/sys/dev/efidev/efirt.c
+++ b/sys/dev/efidev/efirt.c
@@ -730,7 +730,7 @@
 }
 
 static int
-var_get(efi_char *name, struct uuid *vendor, uint32_t *attrib,
+var_get(efi_char *name, efi_guid_t *vendor, uint32_t *attrib,
     size_t *datasize, void *data)
 {
 	struct efirt_callinfo ec;
@@ -754,7 +754,7 @@
 }
 
 static int
-var_nextname(size_t *namesize, efi_char *name, struct uuid *vendor)
+var_nextname(size_t *namesize, efi_char *name, efi_guid_t *vendor)
 {
 	struct efirt_callinfo ec;
 	int error;
@@ -775,7 +775,7 @@
 }
 
 static int
-var_set(efi_char *name, struct uuid *vendor, uint32_t attrib,
+var_set(efi_char *name, efi_guid_t *vendor, uint32_t attrib,
     size_t datasize, void *data)
 {
 	struct efirt_callinfo ec;
diff --git a/sys/dev/xen/efi/pvefi.c b/sys/dev/xen/efi/pvefi.c
--- a/sys/dev/xen/efi/pvefi.c
+++ b/sys/dev/xen/efi/pvefi.c
@@ -122,7 +122,7 @@
 }
 
 static int
-var_get(efi_char *name, struct uuid *vendor, uint32_t *attrib,
+var_get(efi_char *name, efi_guid_t *vendor, uint32_t *attrib,
     size_t *datasize, void *data)
 {
 	struct xen_platform_op op = {
@@ -151,7 +151,7 @@
 }
 
 static int
-var_nextname(size_t *namesize, efi_char *name, struct uuid *vendor)
+var_nextname(size_t *namesize, efi_char *name, efi_guid_t *vendor)
 {
 	struct xen_platform_op op = {
 		.cmd = XENPF_efi_runtime_call,
@@ -177,7 +177,7 @@
 }
 
 static int
-var_set(efi_char *name, struct uuid *vendor, uint32_t attrib,
+var_set(efi_char *name, efi_guid_t *vendor, uint32_t attrib,
     size_t datasize, void *data)
 {
 	struct xen_platform_op op = {
diff --git a/sys/sys/efi.h b/sys/sys/efi.h
--- a/sys/sys/efi.h
+++ b/sys/sys/efi.h
@@ -151,7 +151,7 @@
 };
 
 struct efi_esrt_entry_v1 {
-	struct uuid	fw_class;
+	efi_guid_t	fw_class;
 	uint32_t 	fw_type;
 	uint32_t	fw_version;
 	uint32_t	lowest_supported_fw_version;
@@ -181,11 +181,11 @@
 	efi_status	(*rt_setvirtual)(u_long, u_long, uint32_t,
 	    struct efi_md *) EFIABI_ATTR;
 	efi_status	(*rt_cvtptr)(u_long, void **) EFIABI_ATTR;
-	efi_status	(*rt_getvar)(efi_char *, struct uuid *, uint32_t *,
+	efi_status	(*rt_getvar)(efi_char *, efi_guid_t *, uint32_t *,
 	    u_long *, void *) EFIABI_ATTR;
-	efi_status	(*rt_scanvar)(u_long *, efi_char *, struct uuid *)
+	efi_status	(*rt_scanvar)(u_long *, efi_char *, efi_guid_t *)
 	    EFIABI_ATTR;
-	efi_status	(*rt_setvar)(efi_char *, struct uuid *, uint32_t,
+	efi_status	(*rt_setvar)(efi_char *, efi_guid_t *, uint32_t,
 	    u_long, void *) EFIABI_ATTR;
 	efi_status	(*rt_gethicnt)(uint32_t *) EFIABI_ATTR;
 	efi_status	(*rt_reset)(enum efi_reset, efi_status, u_long,
@@ -267,10 +267,10 @@
 	int 	(*get_waketime)(uint8_t *enabled, uint8_t *pending,
 	    struct efi_tm *tm);
 	int 	(*set_waketime)(uint8_t enable, struct efi_tm *tm);
-	int 	(*var_get)(uint16_t *, struct uuid *, uint32_t *, size_t *,
+	int 	(*var_get)(uint16_t *, efi_guid_t *, uint32_t *, size_t *,
     void *);
-	int 	(*var_nextname)(size_t *, uint16_t *, struct uuid *);
-	int 	(*var_set)(uint16_t *, struct uuid *, uint32_t, size_t, void *);
+	int 	(*var_nextname)(size_t *, uint16_t *, efi_guid_t *);
+	int 	(*var_set)(uint16_t *, efi_guid_t *, uint32_t, size_t, void *);
 };
 extern const struct efi_ops *active_efi_ops;
 
@@ -347,7 +347,7 @@
 	return (active_efi_ops->set_waketime(enable, tm));
 }
 
-static inline int efi_var_get(uint16_t *name, struct uuid *vendor,
+static inline int efi_var_get(uint16_t *name, efi_guid_t *vendor,
     uint32_t *attrib, size_t *datasize, void *data)
 {
 
@@ -357,7 +357,7 @@
 }
 
 static inline int efi_var_nextname(size_t *namesize, uint16_t *name,
-    struct uuid *vendor)
+    efi_guid_t *vendor)
 {
 
 	if (active_efi_ops->var_nextname == NULL)
@@ -365,7 +365,7 @@
 	return (active_efi_ops->var_nextname(namesize, name, vendor));
 }
 
-static inline int efi_var_set(uint16_t *name, struct uuid *vendor,
+static inline int efi_var_set(uint16_t *name, efi_guid_t *vendor,
     uint32_t attrib, size_t datasize, void *data)
 {
 
diff --git a/sys/sys/efiio.h b/sys/sys/efiio.h
--- a/sys/sys/efiio.h
+++ b/sys/sys/efiio.h
@@ -30,38 +30,79 @@
 #include <sys/uuid.h>
 #include <sys/efi.h>
 
-struct efi_get_table_ioc
+/*
+ * The EFI world chose not to use the typical uuid_t defines for its global
+ * universal identifiers. But the textual representation is the same, and we can
+ * use the uuid_* routines to parse and print them. However, all EFI interfaces
+ * for this need to be efi_guid_t so we can share code with EDK2, so the *_ioc
+ * structures in this file are converted to _ioctl structure to transition to
+ * this new requirement. This library is little used outside of FreeBSD and they
+ * will be dropped in 16.
+ */
+_Static_assert(sizeof(struct uuid) == sizeof(efi_guid_t),
+    "uuid_t and efi_guid_t are same bytes, but different elements");
+#if __FreeBSD_version < 1600000 && !defined(_KERNEL)
+#define _WANT_EFI_IOC
+#endif
+
+struct efi_get_table_ioctl
 {
 	void *buf;		/* Pointer to userspace buffer */
-	struct uuid uuid;	/* UUID to look up */
+	efi_guid_t guid;	/* GUID to look up */
 	size_t table_len;	/* Table size */
 	size_t buf_len;		/* Size of the buffer */
 };
 
-struct efi_var_ioc
+struct efi_var_ioctl
 {
 	efi_char *name;		/* User pointer to name, in wide chars */
 	size_t namesize;	/* Number of wide characters in name */
-	struct uuid vendor;	/* Vendor's UUID for variable */
+	efi_guid_t vendor;	/* Vendor's GUID for variable */
 	uint32_t attrib;	/* Attributes */
 	void *data;		/* User pointer to the data */
 	size_t datasize;	/* Number of *bytes* in the data */
 };
 
-struct efi_waketime_ioc
+struct efi_waketime_ioctl
 {
 	struct efi_tm	waketime;
 	uint8_t		enabled;
 	uint8_t		pending;
 };
 
-#define EFIIOC_GET_TABLE	_IOWR('E',  1, struct efi_get_table_ioc)
+#define EFIIOC_GET_TABLE	_IOWR('E',  1, struct efi_get_table_ioctl)
 #define EFIIOC_GET_TIME		_IOR('E',   2, struct efi_tm)
 #define EFIIOC_SET_TIME		_IOW('E',   3, struct efi_tm)
-#define EFIIOC_VAR_GET		_IOWR('E',  4, struct efi_var_ioc)
-#define EFIIOC_VAR_NEXT		_IOWR('E',  5, struct efi_var_ioc)
-#define EFIIOC_VAR_SET		_IOWR('E',  6, struct efi_var_ioc)
-#define EFIIOC_GET_WAKETIME	_IOR('E',   7, struct efi_waketime_ioc)
-#define EFIIOC_SET_WAKETIME	_IOW('E',   8, struct efi_waketime_ioc)
+#define EFIIOC_VAR_GET		_IOWR('E',  4, struct efi_var_ioctl)
+#define EFIIOC_VAR_NEXT		_IOWR('E',  5, struct efi_var_ioctl)
+#define EFIIOC_VAR_SET		_IOWR('E',  6, struct efi_var_ioctl)
+#define EFIIOC_GET_WAKETIME	_IOR('E',   7, struct efi_waketime_ioctl)
+#define EFIIOC_SET_WAKETIME	_IOW('E',   8, struct efi_waketime_ioctl)
+
+#ifdef _WANT_EFI_IOC
+struct efi_get_table_ioc
+{
+	void *buf;		/* Pointer to userspace buffer */
+	struct uuid uuid;	/* GUID to look up */
+	size_t table_len;	/* Table size */
+	size_t buf_len;		/* Size of the buffer */
+};
+
+struct efi_var_ioc
+{
+	efi_char *name;		/* User pointer to name, in wide chars */
+	size_t namesize;	/* Number of wide characters in name */
+	struct uuid vendor;	/* Vendor's GUID for variable */
+	uint32_t attrib;	/* Attributes */
+	void *data;		/* User pointer to the data */
+	size_t datasize;	/* Number of *bytes* in the data */
+};
+
+_Static_assert(sizeof(struct efi_get_table_ioc) == sizeof(struct efi_get_table_ioctl),
+    "Old and new struct table defines must be the same size");
+_Static_assert(sizeof(struct efi_var_ioc) == sizeof(struct efi_var_ioctl),
+    "Old and new struct var defines must be the same size");
+#define efi_waketime_ioc efi_waketime_ioctl
+#endif
 
 #endif /* _SYS_EFIIO_H_ */