diff --git a/lldb/include/lldb/Utility/Reproducer.h b/lldb/include/lldb/Utility/Reproducer.h
index 14b9309f16d5..60e6ffe65a59 100644
--- a/lldb/include/lldb/Utility/Reproducer.h
+++ b/lldb/include/lldb/Utility/Reproducer.h
@@ -126,6 +126,7 @@ public:
     m_os << t;
     if (newline)
       m_os << '\n';
+    m_os.flush();
   }
 
   const FileSpec &GetFilename() { return m_filename; }
diff --git a/lldb/include/lldb/Utility/ReproducerInstrumentation.h b/lldb/include/lldb/Utility/ReproducerInstrumentation.h
index 6835e8e52ef6..f90ce4bc767a 100644
--- a/lldb/include/lldb/Utility/ReproducerInstrumentation.h
+++ b/lldb/include/lldb/Utility/ReproducerInstrumentation.h
@@ -542,7 +542,9 @@ public:
     SerializeAll(tail...);
   }
 
-  void SerializeAll() {}
+  void SerializeAll() {
+    m_stream.flush();
+  }
 
 private:
   /// Serialize pointers. We need to differentiate between pointers to