diff --git a/tools/src/main/java/org/bitcoinj/tools/BuildCheckpoints.java b/tools/src/main/java/org/bitcoinj/tools/BuildCheckpoints.java
index 51b28343a..1e54d1257 100644
--- a/tools/src/main/java/org/bitcoinj/tools/BuildCheckpoints.java
+++ b/tools/src/main/java/org/bitcoinj/tools/BuildCheckpoints.java
@@ -211,7 +211,14 @@ public class BuildCheckpoints {
     }
 
     private static void sanityCheck(File file, int expectedSize) throws IOException {
-        CheckpointManager manager = new CheckpointManager(params, new FileInputStream(file));
+        FileInputStream fis = new FileInputStream(file);
+        CheckpointManager manager;
+        try {
+            manager = new CheckpointManager(params, fis);
+        } finally {
+            fis.close();
+        }
+
         checkState(manager.numCheckpoints() == expectedSize);
 
         if (params.getId().equals(NetworkParameters.ID_MAINNET)) {