diff --git a/src/main/java/org/broadinstitute/hellbender/engine/FeatureDataSource.java b/src/main/java/org/broadinstitute/hellbender/engine/FeatureDataSource.java
index 8e2e89e8898..b861186eb51 100644
--- a/src/main/java/org/broadinstitute/hellbender/engine/FeatureDataSource.java
+++ b/src/main/java/org/broadinstitute/hellbender/engine/FeatureDataSource.java
@@ -334,7 +334,10 @@ public FeatureDataSource(final FeatureInput<T> featureInput, final int queryLook
 
         this.currentIterator = null;
         this.intervalsForTraversal = null;
-        this.queryCache = new LocatableCache<>(featureInput.getName(), new DrivingFeatureInputCacheStrategy<>(queryLookaheadBases, this::refillQueryCache));
+        this.queryCache = new LocatableCache<>(
+                featureInput.getName(),
+                new DrivingFeatureInputCacheStrategy<>(queryLookaheadBases,
+                        (Function<Locatable, Iterator<T>> & Serializable) this::refillQueryCache));
     }
 
     final void printCacheStats() {