diff --git a/src/bvar/collector.h b/src/bvar/collector.h
index a334f5da..56db7214 100644
--- a/src/bvar/collector.h
+++ b/src/bvar/collector.h
@@ -47,6 +47,7 @@ class Collected;
 // For processing samples in batch before dumping.
 class CollectorPreprocessor {
 public:
+    virtual ~CollectorPreprocessor() = default;
     virtual void process(std::vector<Collected*>& samples) = 0;
 };