diff --git a/external/libfdt/fix-strnlen.patch b/external/libfdt/fix-strnlen.patch
new file mode 100644
index 0000000..7a7bb7d
--- /dev/null
+++ b/external/libfdt/fix-strnlen.patch
@@ -0,0 +1,30 @@
+This patch enables using libfdt's strlen() implementation.
+
+diff --git i/libfdt/libfdt_env.h w/libfdt/libfdt_env.h
+index 73b6d40..3a2d38c 100644
+--- i/libfdt/libfdt_env.h
++++ w/libfdt/libfdt_env.h
+@@ -66,13 +66,6 @@ static inline fdt64_t cpu_to_fdt64(uint64_t x)
+ #undef CPU_TO_FDT16
+ #undef EXTRACT_BYTE
+
+-#ifdef __APPLE__
+-#include <AvailabilityMacros.h>
+-
+-/* strnlen() is not available on Mac OS < 10.7 */
+-# if !defined(MAC_OS_X_VERSION_10_7) || (MAC_OS_X_VERSION_MAX_ALLOWED < \
+-                                         MAC_OS_X_VERSION_10_7)
+-
+ #define strnlen fdt_strnlen
+
+ /*
+@@ -88,9 +81,4 @@ static inline size_t fdt_strnlen(const char *string, size_t max_count)
+     return p ? p - string : max_count;
+ }
+
+-#endif /* !defined(MAC_OS_X_VERSION_10_7) || (MAC_OS_X_VERSION_MAX_ALLOWED <
+-          MAC_OS_X_VERSION_10_7) */
+-
+-#endif /* __APPLE__ */
+-
+ #endif /* LIBFDT_ENV_H */