diff --git a/gstreamer/src/buffer_cursor.rs b/gstreamer/src/buffer_cursor.rs
index 88ae37459..d393b0d53 100644
--- a/gstreamer/src/buffer_cursor.rs
+++ b/gstreamer/src/buffer_cursor.rs
@@ -218,6 +218,13 @@ macro_rules! define_write_impl(
         }
 
         fn flush(&mut self) -> Result<(), io::Error> {
+            if !self.map_info.memory.is_null() {
+                unsafe {
+                    gst_sys::gst_memory_unmap(self.map_info.memory, &mut self.map_info);
+                    self.map_info.memory = ptr::null_mut();
+                }
+            }
+
             Ok(())
         }
     }