diff --git a/cmd/gendb/main.go b/cmd/gendb/main.go
index 0d175a4..065df03 100644
--- a/cmd/gendb/main.go
+++ b/cmd/gendb/main.go
@@ -114,7 +114,7 @@
 	}
 
 	// Write a directory containing entries by ID.
-	idDir := filepath.Join(*jsonDir, "byID")
+	idDir := filepath.Join(*jsonDir, "ID")
 	if err := os.MkdirAll(idDir, 0700); err != nil {
 		failf("failed to create directory %q: %v", idDir, err)
 	}