diff --git a/src/include/ipxe/efi/efi.h b/src/include/ipxe/efi/efi.h
index 880872aa..46b66690 100644
--- a/src/include/ipxe/efi/efi.h
+++ b/src/include/ipxe/efi/efi.h
@@ -54,12 +54,7 @@
 /** An EFI protocol used by iPXE */
 struct efi_protocol {
 	/** GUID */
-	union {
-		/** EFI protocol GUID */
-		EFI_GUID guid;
-		/** UUID structure understood by iPXE */
-		union uuid uuid;
-	} u;
+	EFI_GUID guid;
 	/** Variable containing pointer to protocol structure */
 	void **protocol;
 };
@@ -77,7 +72,7 @@ struct efi_protocol {
  */
 #define EFI_REQUIRE_PROTOCOL( _protocol, _ptr )				     \
 	struct efi_protocol __ ## _protocol __efi_protocol = {		     \
-		.u.guid = _protocol ## _GUID,				     \
+		.guid = _protocol ## _GUID,				     \
 		.protocol = ( ( void ** ) ( void * )			     \
 			      ( ( (_ptr) == ( ( _protocol ** ) (_ptr) ) ) ?  \
 				(_ptr) : (_ptr) ) ),			     \
@@ -86,12 +81,7 @@ struct efi_protocol {
 /** An EFI configuration table used by iPXE */
 struct efi_config_table {
 	/** GUID */
-	union {
-		/** EFI configuration table GUID */
-		EFI_GUID guid;
-		/** UUID structure understood by iPXE */
-		union uuid uuid;
-	} u;
+	EFI_GUID guid;
 	/** Variable containing pointer to configuration table */
 	void **table;
 	/** Table is required for operation */
@@ -113,7 +103,7 @@ struct efi_config_table {
  */
 #define EFI_USE_TABLE( _table, _ptr, _required )			     \
 	struct efi_config_table __ ## _table __efi_config_table = {	     \
-		.u.guid = _table ## _GUID,				     \
+		.guid = _table ## _GUID,				     \
 		.table = ( ( void ** ) ( void * ) (_ptr) ),		     \
 		.required = (_required),				     \
 	}
@@ -140,6 +130,7 @@ extern EFI_LOADED_IMAGE_PROTOCOL *efi_loaded_image;
 extern EFI_SYSTEM_TABLE *efi_systab;
 
 extern const char * efi_strerror ( EFI_STATUS efirc );
+extern const char * efi_guid_ntoa ( EFI_GUID *guid );
 
 extern void dbg_efi_protocols ( EFI_HANDLE handle );
 extern void dbg_efi_devpath ( EFI_DEVICE_PATH_PROTOCOL *path );
diff --git a/src/interface/efi/efi_debug.c b/src/interface/efi/efi_debug.c
index 7f3c115d..a7ba7e2e 100644
--- a/src/interface/efi/efi_debug.c
+++ b/src/interface/efi/efi_debug.c
@@ -27,6 +27,8 @@ FILE_LICENCE ( GPL2_OR_LATER );
  */
 
 #include <stdio.h>
+#include <string.h>
+#include <ipxe/uuid.h>
 #include <ipxe/efi/efi.h>
 #include <ipxe/efi/efi_driver.h>
 #include <ipxe/efi/Protocol/DevicePath.h>
@@ -36,6 +38,24 @@ FILE_LICENCE ( GPL2_OR_LATER );
 static EFI_DEVICE_PATH_TO_TEXT_PROTOCOL *efidpt;
 EFI_REQUIRE_PROTOCOL ( EFI_DEVICE_PATH_TO_TEXT_PROTOCOL, &efidpt );
 
+/**
+ * Convert GUID to a printable string
+ *
+ * @v guid		GUID
+ * @ret string		Printable string
+ */
+const char * efi_guid_ntoa ( EFI_GUID *guid ) {
+	union {
+		union uuid uuid;
+		EFI_GUID guid;
+	} u;
+
+	/* Convert GUID to standard endianness */
+	memcpy ( &u.guid, guid, sizeof ( u.guid ) );
+	uuid_mangle ( &u.uuid );
+	return uuid_ntoa ( &u.uuid );
+}
+
 /**
  * Print list of protocol handlers attached to a handle
  *
@@ -57,9 +77,8 @@ void dbg_efi_protocols ( EFI_HANDLE handle ) {
 	}
 
 	/* Dump list of protocols */
-	for ( i = 0 ; i < count ; i++ ) {
-		printf ( "%s\n", uuid_ntoa ( ( union uuid * ) protocols[i] ) );
-	}
+	for ( i = 0 ; i < count ; i++ )
+		printf ( "%s\n", efi_guid_ntoa ( protocols[i] ) );
 
 	/* Free list */
 	bs->FreePool ( protocols );
diff --git a/src/interface/efi/efi_file.c b/src/interface/efi/efi_file.c
index ffe25fd6..6f9d44f8 100644
--- a/src/interface/efi/efi_file.c
+++ b/src/interface/efi/efi_file.c
@@ -414,8 +414,7 @@ static EFI_STATUS EFIAPI efi_file_get_info ( EFI_FILE_PROTOCOL *this,
 	} else {
 
 		DBGC ( file, "EFIFILE %s cannot get information of type %s\n",
-		       efi_file_name ( file ),
-		       uuid_ntoa ( ( union uuid * ) type ) );
+		       efi_file_name ( file ), efi_guid_ntoa ( type ) );
 		return EFI_UNSUPPORTED;
 	}
 }
@@ -435,7 +434,7 @@ efi_file_set_info ( EFI_FILE_PROTOCOL *this, EFI_GUID *type,
 	struct efi_file *file = container_of ( this, struct efi_file, file );
 
 	DBGC ( file, "EFIFILE %s cannot set information of type %s\n",
-	       efi_file_name ( file ), uuid_ntoa ( ( union uuid * ) type ) );
+	       efi_file_name ( file ), efi_guid_ntoa ( type ) );
 	return EFI_WRITE_PROTECTED;
 }
 
diff --git a/src/interface/efi/efi_init.c b/src/interface/efi/efi_init.c
index aaf89471..48cac538 100644
--- a/src/interface/efi/efi_init.c
+++ b/src/interface/efi/efi_init.c
@@ -121,13 +121,14 @@ EFI_STATUS efi_init ( EFI_HANDLE image_handle,
 
 	/* Look up used protocols */
 	for_each_table_entry ( prot, EFI_PROTOCOLS ) {
-		if ( ( efirc = bs->LocateProtocol ( &prot->u.guid, NULL,
+		if ( ( efirc = bs->LocateProtocol ( &prot->guid, NULL,
 						    prot->protocol ) ) == 0 ) {
 			DBGC ( systab, "EFI protocol %s is at %p\n",
-			       uuid_ntoa ( &prot->u.uuid ), *(prot->protocol));
+			       efi_guid_ntoa ( &prot->guid ),
+			       *(prot->protocol) );
 		} else {
 			DBGC ( systab, "EFI does not provide protocol %s\n",
-			       uuid_ntoa ( &prot->u.uuid ) );
+			       efi_guid_ntoa ( &prot->guid ) );
 			/* All protocols are required */
 			return efirc;
 		}
@@ -135,12 +136,12 @@ EFI_STATUS efi_init ( EFI_HANDLE image_handle,
 
 	/* Look up used configuration tables */
 	for_each_table_entry ( tab, EFI_CONFIG_TABLES ) {
-		if ( ( *(tab->table) = efi_find_table ( &tab->u.guid ) ) ) {
+		if ( ( *(tab->table) = efi_find_table ( &tab->guid ) ) ) {
 			DBGC ( systab, "EFI configuration table %s is at %p\n",
-			       uuid_ntoa ( &tab->u.uuid ), *(tab->table) );
+			       efi_guid_ntoa ( &tab->guid ), *(tab->table) );
 		} else {
 			DBGC ( systab, "EFI does not provide configuration "
-			       "table %s\n", uuid_ntoa ( &tab->u.uuid ) );
+			       "table %s\n", efi_guid_ntoa ( &tab->guid ) );
 			if ( tab->required )
 				return EFI_NOT_AVAILABLE_YET;
 		}