diff --git a/disas.c b/disas.c
index 34b0474056..3a5549d2b6 100644
--- a/disas.c
+++ b/disas.c
@@ -110,7 +110,7 @@ bfd_vma bfd_getb32 (const bfd_byte *addr)
 
 /* Disassemble this for me please... (debugging). 'flags' is only used
    for i386: non zero means 16 bit code */
-void target_disas(FILE *out, target_ulong code, unsigned long size, int flags)
+void target_disas(FILE *out, target_ulong code, target_ulong size, int flags)
 {
     target_ulong pc;
     int count;
diff --git a/disas.h b/disas.h
index ef80fd700e..32da4ebcb3 100644
--- a/disas.h
+++ b/disas.h
@@ -3,7 +3,7 @@
 
 /* Disassemble this for me please... (debugging). */
 void disas(FILE *out, void *code, unsigned long size);
-void target_disas(FILE *out, target_ulong code, unsigned long size, int flags);
+void target_disas(FILE *out, target_ulong code, target_ulong size, int flags);
 void monitor_disas(target_ulong pc, int nb_insn, int is_physical, int flags);
 
 /* Look up symbol for debugging purpose.  Returns "" if unknown. */