diff --git a/src/system/boot/platform/bios_ia32/multiboot.h b/src/system/boot/platform/bios_ia32/multiboot.h
index 5f22bcaad8..fc42af7c39 100644
--- a/src/system/boot/platform/bios_ia32/multiboot.h
+++ b/src/system/boot/platform/bios_ia32/multiboot.h
@@ -6,10 +6,15 @@
 #define _MULTIBOOT_H
 
 
+#ifndef __ASSEMBLER__
+
 #include <SupportDefs.h>
 
+#endif /* __ASSEMBLER__ */
+
 
 /* minimal part of the MultiBoot API */
+/* we use the official names */
 
 /* magics */
 #define MULTIBOOT_MAGIC 0x1badb002
@@ -28,6 +33,7 @@
 #define MULTIBOOT_INFO_MODS 0x00000008
 #define MULTIBOOT_INFO_MEM_MAP 0x00000040
 
+#ifndef __ASSEMBLER__
 
 /* info struct passed to the loader */
 struct multiboot_info {
@@ -65,5 +71,6 @@ extern status_t parse_multiboot_commandline(struct stage2_args *args);
 }
 #endif
 
+#endif /* __ASSEMBLER__ */
 
 #endif /* _MULTIBOOT_H */
diff --git a/src/system/boot/platform/bios_ia32/shell.S b/src/system/boot/platform/bios_ia32/shell.S
index 32d3b633e3..405be7987d 100644
--- a/src/system/boot/platform/bios_ia32/shell.S
+++ b/src/system/boot/platform/bios_ia32/shell.S
@@ -14,19 +14,9 @@
  *	the entry function of the embedded ELF part of the loader.
  */
 
-#define GLOBAL(x) .globl x ; x
+#include "multiboot.h"
 
-// GRUB-compatible MultiBoot info
-// we use the official names
-#define MULTIBOOT_MAGIC 0x1badb002
-#define MULTIBOOT_MAGIC2 0x2badb002
-// header flags
-#define MULTIBOOT_PAGE_ALIGN 0x00000001
-#define MULTIBOOT_MEMORY_INFO 0x00000002
-#define MULTIBOOT_VIDEO_MODE 0x00000004
-#define MULTIBOOT_AOUT_KLUDGE 0x00010000
-// info flags
-#define MULTIBOOT_INFO_BOOTDEV 0x00000002
+#define GLOBAL(x) .globl x ; x
 
 #define OUR_MB_FLAGS (MULTIBOOT_PAGE_ALIGN \
 	| MULTIBOOT_MEMORY_INFO \