diff --git a/src/octoprint/server/api/files.py b/src/octoprint/server/api/files.py
index b615c173..5a2ff6e1 100644
--- a/src/octoprint/server/api/files.py
+++ b/src/octoprint/server/api/files.py
@@ -51,14 +51,17 @@ def _getFileList(origin):
 
 		files = []
 		if sdFileList is not None:
-			for sdFile in sdFileList:
-				files.append({
+			for sdFile, sdSize in sdFileList:
+				file = {
 					"name": sdFile,
 					"origin": FileDestinations.SDCARD,
 					"refs": {
 						"resource": url_for(".readGcodeFile", target=FileDestinations.SDCARD, filename=sdFile, _external=True)
 					}
-				})
+				}
+				if sdSize is not None:
+					file.update({"size": sdSize})
+				files.append(file)
 	else:
 		files = gcodeManager.getAllFileData()
 		for file in files:
diff --git a/src/octoprint/settings.py b/src/octoprint/settings.py
index c182d983..54285cb3 100644
--- a/src/octoprint/settings.py
+++ b/src/octoprint/settings.py
@@ -147,7 +147,8 @@ default_settings = {
 			"numExtruders": 1,
 			"includeCurrentToolInTemps": True,
 			"hasBed": True,
-			"repetierStyleTargetTemperature": False
+			"repetierStyleTargetTemperature": False,
+			"extendedSdFileList": False
 		}
 	}
 }
diff --git a/src/octoprint/util/comm.py b/src/octoprint/util/comm.py
index 42c39624..b6f4bcaa 100644
--- a/src/octoprint/util/comm.py
+++ b/src/octoprint/util/comm.py
@@ -645,13 +645,28 @@ class MachineCom(object):
 
 				##~~ SD file list
 				# if we are currently receiving an sd file list, each line is just a filename, so just read it and abort processing
-				if self._sdFileList and isGcodeFileName(line.strip().lower()) and not 'End file list' in line:
-					filename = line.strip().lower()
-					if filterNonAscii(filename):
-						self._logger.warn("Got a file from printer's SD that has a non-ascii filename (%s), that shouldn't happen according to the protocol" % filename)
+				if self._sdFileList and not "End file list" in line:
+					fileinfo = line.strip().split(None, 2)
+					if len(fileinfo) > 1:
+						# we got extended file information here, so let's split filename and size and try to make them a bit nicer
+						filename, size = fileinfo
+						filename = filename.lower()
+						try:
+							size = int(size)
+						except ValueError:
+							# whatever that was, it was not an integer, so we'll just ignore it and set size to None
+							size = None
 					else:
-						self._sdFiles.append(filename)
-					continue
+						# no extended file information, so only the filename is there and we set size to None
+						filename = fileinfo[0].lower()
+						size = None
+
+					if isGcodeFileName(filename):
+						if filterNonAscii(filename):
+							self._logger.warn("Got a file from printer's SD that has a non-ascii filename (%s), that shouldn't happen according to the protocol" % filename)
+						else:
+							self._sdFiles.append((filename, size))
+						continue
 
 				##~~ Temperature processing
 				if ' T:' in line or line.startswith('T:') or ' T0:' in line or line.startswith('T0:'):
diff --git a/src/octoprint/util/virtual.py b/src/octoprint/util/virtual.py
index cc0b34b2..021bc5b6 100644
--- a/src/octoprint/util/virtual.py
+++ b/src/octoprint/util/virtual.py
@@ -155,8 +155,20 @@ class VirtualPrinter():
 
 	def _listSd(self):
 		self.readList.append("Begin file list")
-		for osFile in os.listdir(self._virtualSd):
-			self.readList.append(osFile.upper())
+		if settings().getBoolean(["devel", "virtualPrinter", "extendedSdFileList"]):
+			self.readList.extend(
+				map(
+					lambda x: "%s %d" % (x.upper(), os.stat(os.path.join(self._virtualSd, x)).st_size),
+					os.listdir(self._virtualSd)
+				)
+			)
+		else:
+			self.readList.extend(
+				map(
+					lambda x: x.upper(),
+					os.listdir(self._virtualSd)
+				)
+			)
 		self.readList.append("End file list")
 		self._sendOk()