diff --git a/include/libfdt_env.h b/include/libfdt_env.h
index 273b5d3..6c6845f 100644
--- a/include/libfdt_env.h
+++ b/include/libfdt_env.h
@@ -23,6 +23,12 @@
 #define fdt64_to_cpu(x)		be64_to_cpu(x)
 #define cpu_to_fdt64(x)		cpu_to_be64(x)
 
+#ifdef __UBOOT__
+#include <vsprintf.h>
+
+#define strtoul(cp, endp, base)	simple_strtoul(cp, endp, base)
+#endif
+
 /* adding a ramdisk needs 0x44 bytes in version 2008.10 */
 #define FDT_RAMDISK_OVERHEAD	0x80