diff --git a/iaa.h b/iaa.h
index ecc3a87..674fa15 100644
--- a/iaa.h
+++ b/iaa.h
@@ -23,6 +23,10 @@ class IAAJob {
     }
   }
 
+  // Prevent copying a job
+  IAAJob(const IAAJob&) = delete;
+  IAAJob& operator=(const IAAJob&) = delete;
+
   qpl_job* GetJob(qpl_path_t execution_path) {
     if (jobs_[execution_path] == nullptr) {
       InitJob(execution_path);
diff --git a/qat.h b/qat.h
index 66c8406..3b7be4e 100644
--- a/qat.h
+++ b/qat.h
@@ -18,6 +18,11 @@ class QATJob {
  public:
   QATJob() {}
   ~QATJob() { Close(); }
+
+  // Prevent copying a job
+  QATJob(const QATJob&) = delete;
+  QATJob& operator=(const QATJob&) = delete;
+
   QzSession_T* GetQATSession(int window_bits, bool gzip_ext);
   void CloseQATSession(int window_bits, bool gzip_ext);