diff --git a/arm64.c b/arm64.c
index d1c9c3e8..34c8c591 100644
--- a/arm64.c
+++ b/arm64.c
@@ -267,7 +267,10 @@ arm64_init(int when)
 	case POST_GDB:
 		arm64_calc_virtual_memory_ranges();
 		machdep->section_size_bits = _SECTION_SIZE_BITS;
-		machdep->max_physmem_bits = _MAX_PHYSMEM_BITS;
+		if (THIS_KERNEL_VERSION >= LINUX(3,17,0))
+			machdep->max_physmem_bits = _MAX_PHYSMEM_BITS_3_17;
+		else
+			machdep->max_physmem_bits = _MAX_PHYSMEM_BITS;
 		ms = machdep->machspec;
 
 		if (THIS_KERNEL_VERSION >= LINUX(4,0,0)) {
diff --git a/defs.h b/defs.h
index a1746cc8..a09fa9a9 100644
--- a/defs.h
+++ b/defs.h
@@ -2965,6 +2965,7 @@ typedef signed int s32;
 
 #define _SECTION_SIZE_BITS      30
 #define _MAX_PHYSMEM_BITS       40
+#define _MAX_PHYSMEM_BITS_3_17  48
 
 typedef unsigned long long __u64;
 typedef unsigned long long u64;