diff --git a/bitbake/lib/bb/cache.py b/bitbake/lib/bb/cache.py
index 28e8a87455..e7eeb4f505 100644
--- a/bitbake/lib/bb/cache.py
+++ b/bitbake/lib/bb/cache.py
@@ -462,6 +462,10 @@ class Cache(NoCache):
                         self.depends_cache[key] = [value]
                     # only fire events on even percentage boundaries
                     current_progress = cachefile.tell() + previous_progress
+                    if current_progress > cachesize:
+                        # we might have calculated incorrect total size because a file
+                        # might've been written out just after we checked its size
+                        cachesize = current_progress
                     current_percent = 100 * current_progress / cachesize
                     if current_percent > previous_percent:
                         previous_percent = current_percent