diff --git a/pandora_client/__init__.py b/pandora_client/__init__.py
index cf816d1..2eefd7b 100755
--- a/pandora_client/__init__.py
+++ b/pandora_client/__init__.py
@@ -115,6 +115,13 @@ def ignore_file(client, path):
         return True
     return False
 
+def is_oshash(oshash):
+    try:
+        int(oshash, 16)
+    except:
+        return False
+    return len(oshash) == 16
+
 def hide_cursor():
     sys.stdout.write("\033[?25l")
     sys.stdout.flush()
@@ -654,6 +661,9 @@ class Client(object):
                             'filename': filename
                         })
                     data.append(oshash)
+                elif not is_oshash(arg):
+                    print 'file not found "%s"' % arg
+                    sys.exit(1)
                 else:
                     data.append(arg)
             files = []