diff --git a/tools/releasetools/sign_target_files_apks b/tools/releasetools/sign_target_files_apks
index 00693b8..ab24706 100755
--- a/tools/releasetools/sign_target_files_apks
+++ b/tools/releasetools/sign_target_files_apks
@@ -235,8 +235,9 @@
       elif key == "ro.build.display.id":
         # change, eg, "JWR66N dev-keys" to "JWR66N"
         value = value.split()
-        if len(value) == 2 and value[1].endswith("-keys"):
-          value = value[0]
+        if len(value) >  1 and value[-1].endswith("-keys"):
+          value.pop()
+        value = " ".join(value)
       line = key + "=" + value
     if line != original_line:
       print "  replace: ", original_line