diff --git a/fastboot/fastboot.cpp b/fastboot/fastboot.cpp
index 783cd19..f720dda 100644
--- a/fastboot/fastboot.cpp
+++ b/fastboot/fastboot.cpp
@@ -1391,6 +1391,7 @@
 
 class ImageSource {
   public:
+    virtual ~ImageSource() {};
     virtual bool ReadFile(const std::string& name, std::vector<char>* out) const = 0;
     virtual unique_fd OpenFile(const std::string& name) const = 0;
 };