diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index 76c2c97cb..c5758c7f0 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -509,7 +509,7 @@ class BuildInfo(object):
     return self.GetBuildProp(key)
 
   def GetPartitionFingerprint(self, partition):
-    return self._partition_fingerprints.get(partition, None)
+    return self._partition_fingerprints.get(partition, self.CalculateFingerprint())
 
   def CalculatePartitionFingerprint(self, partition):
     try: