diff --git a/tools/releasetools/check_target_files_signatures b/tools/releasetools/check_target_files_signatures
index 4e83129..7cb3e8a 100755
--- a/tools/releasetools/check_target_files_signatures
+++ b/tools/releasetools/check_target_files_signatures
@@ -347,8 +347,8 @@
     for i in all:
       if i in self.apks:
         if i in other.apks:
-          # in both; should have at least one cert in common
-          if not (self.apks[i].cert & other.apks[i].cert):
+          # in both; should have same set of certs
+          if self.apks[i].certs != other.apks[i].certs:
             by_certpair.setdefault((other.apks[i].certs,
                                     self.apks[i].certs), []).append(i)
         else: