diff --git a/Kernel/DoubleBuffer.h b/Kernel/DoubleBuffer.h
index 3d775be2d4c..2d735b34dcd 100644
--- a/Kernel/DoubleBuffer.h
+++ b/Kernel/DoubleBuffer.h
@@ -58,7 +58,7 @@ private:
 
     struct InnerBuffer {
         u8* data { nullptr };
-        size_t size;
+        size_t size { 0 };
     };
 
     InnerBuffer* m_write_buffer { nullptr };