diff --git a/bunker/files/tarfile.py b/bunker/files/tarfile.py
index ffa5d36..5afdd71 100644
--- a/bunker/files/tarfile.py
+++ b/bunker/files/tarfile.py
@@ -98,3 +98,16 @@ class RewriteableTarFile(object):
 			new_handle.addfile(member, handle.extractfile(member))
 		new_handle.close()
 
+	def has_file(self, member):
+		if(isinstance(member, tarfile.TarInfo)):
+			member_name = member.name
+		elif(isinstance(member, str)):
+			member_name = member
+		else:
+			raise TypeError("member must be TarInfo or str, not {}".format(type(member)))
+
+		handle = self._open_handle()
+
+		return member_name in handle.getnames()
+
+