diff --git a/protobuf/fh.proto b/protobuf/fh.proto
index eb73d66cf..bda17c943 100644
--- a/protobuf/fh.proto
+++ b/protobuf/fh.proto
@@ -1,3 +1,5 @@
+import "opts.proto";
+
 enum fh_entry_sizes {
 	min_entries			= 16;
 }
@@ -13,7 +15,7 @@ message fh_entry {
 }
 
 message irmap_cache_entry {
-	required uint32		dev	= 1;
+	required uint32		dev	= 1 [(criu).dev = true, (criu).odev = true];
 	required uint64		inode	= 2;
 	required string		path	= 3;
 }
diff --git a/protobuf/fsnotify.proto b/protobuf/fsnotify.proto
index f0835603b..fbe724cb3 100644
--- a/protobuf/fsnotify.proto
+++ b/protobuf/fsnotify.proto
@@ -7,7 +7,7 @@ message inotify_wd_entry {
 	required uint64		i_ino		= 2;
 	required uint32		mask		= 3 [(criu).hex = true];
 	required uint32		ignored_mask	= 4 [(criu).hex = true];
-	required uint32		s_dev		= 5;
+	required uint32		s_dev		= 5 [(criu).dev = true];
 	required uint32		wd		= 6;
 	required fh_entry	f_handle	= 7;
 }
@@ -40,7 +40,7 @@ message fanotify_mark_entry {
 	required uint32		mflags		= 3 [(criu).hex = true];
 	required uint32		mask		= 4 [(criu).hex = true];
 	required uint32		ignored_mask	= 5 [(criu).hex = true];
-	required uint32		s_dev		= 6;
+	required uint32		s_dev		= 6 [(criu).dev = true];
 
 	optional fanotify_inode_mark_entry ie	= 7;
 	optional fanotify_mount_mark_entry me	= 8;
diff --git a/protobuf/ghost-file.proto b/protobuf/ghost-file.proto
index 3bfbbad49..a600a4374 100644
--- a/protobuf/ghost-file.proto
+++ b/protobuf/ghost-file.proto
@@ -1,9 +1,11 @@
+import "opts.proto";
+
 message ghost_file_entry {
 	required uint32		uid		= 1;
 	required uint32		gid		= 2;
 	required uint32		mode		= 3;
 
-	optional uint32		dev		= 4;
+	optional uint32		dev		= 4 [(criu).dev = true];
 	optional uint64		ino		= 5;
-	optional uint32		rdev		= 6;
+	optional uint32		rdev		= 6 [(criu).dev = true, (criu).odev = true];
 }
diff --git a/protobuf/mnt.proto b/protobuf/mnt.proto
index 12582e9d5..390228326 100644
--- a/protobuf/mnt.proto
+++ b/protobuf/mnt.proto
@@ -24,7 +24,7 @@ enum fstype {
 message mnt_entry {
 	required uint32		fstype			= 1;
 	required uint32		mnt_id			= 2;
-	required uint32		root_dev		= 3;
+	required uint32		root_dev		= 3 [(criu).dev = true];
 	required uint32		parent_mnt_id		= 4;
 	required uint32		flags			= 5 [(criu).hex = true];
 
diff --git a/protobuf/opts.proto b/protobuf/opts.proto
index 12e4ba497..18ea7b648 100644
--- a/protobuf/opts.proto
+++ b/protobuf/opts.proto
@@ -4,6 +4,8 @@ message CRIU_Opts {
 	optional bool hex = 1; // Idicate that CRIT should treat this field as hex.
 	optional bool ipadd = 2; // The field is IPv4/v6 address
 	optional string flags = 3;
+	optional bool dev = 4; // Device major:minor packed
+	optional bool odev = 5; // ... in old format
 }
 
 extend google.protobuf.FieldOptions {
diff --git a/pycriu/images/pb2dict.py b/pycriu/images/pb2dict.py
index 4e717f19a..ddd0f9103 100644
--- a/pycriu/images/pb2dict.py
+++ b/pycriu/images/pb2dict.py
@@ -3,6 +3,7 @@ import opts_pb2
 import ipaddr
 import socket
 import collections
+import os
 
 # pb2dict and dict2pb are methods to convert pb to/from dict.
 # Inspired by:
@@ -52,6 +53,12 @@ def _marked_as_ip(field):
 def _marked_as_flags(field):
 	return field.GetOptions().Extensions[opts_pb2.criu].flags
 
+def _marked_as_dev(field):
+	return field.GetOptions().Extensions[opts_pb2.criu].dev
+
+def _marked_as_odev(field):
+	return field.GetOptions().Extensions[opts_pb2.criu].odev
+
 mmap_prot_map = [
 	('PROT_READ',	0x1),
 	('PROT_WRITE',	0x2),
@@ -92,6 +99,21 @@ def unmap_flags(value, flags_map):
 	bd = dict(flags_map)
 	return sum(map(lambda x: int(str(bd.get(x, x)), 0), map(lambda x: x.strip(), value.split('|'))))
 
+kern_minorbits = 20 # This is how kernel encodes dev_t in new format
+
+def decode_dev(field, value):
+	if _marked_as_odev(field):
+		return "%d:%d" % (os.major(value), os.minor(value))
+	else:
+		return "%d:%d" % (value >> kern_minorbits, value & ((1 << kern_minorbits) - 1))
+
+def encode_dev(field, value):
+	dev = map(lambda x: int(x), value.split(':'))
+	if _marked_as_odev(field):
+		return os.makedev(dev[0], dev[1])
+	else:
+		return dev[0] << kern_minorbits | dev[1]
+
 def _pb2dict_cast(field, value, pretty = False, is_hex = False):
 	if not is_hex:
 		is_hex = _marked_as_hex(field)
@@ -110,6 +132,9 @@ def _pb2dict_cast(field, value, pretty = False, is_hex = False):
 				# should be stored in hex string format.
 				return "0x%x" % value
 
+			if _marked_as_dev(field):
+				return decode_dev(field, value)
+
 			flags = _marked_as_flags(field)
 			if flags:
 				try:
@@ -164,6 +189,9 @@ def _dict2pb_cast(field, value):
 	elif field.type in _basic_cast:
 		cast = _basic_cast[field.type]
 		if (cast == int or cast == long) and isinstance(value, unicode):
+			if _marked_as_dev(field):
+				return encode_dev(field, value)
+
 			flags = _marked_as_flags(field)
 			if flags:
 				try: