diff --git a/src/libguac/encode-png.c b/src/libguac/encode-png.c
index d3632f28..516c1f6c 100644
--- a/src/libguac/encode-png.c
+++ b/src/libguac/encode-png.c
@@ -396,6 +396,8 @@ int guac_png_write(guac_socket* socket, guac_stream* stream,
         free(png_rows[y]);
     free(png_rows);
 
+    /* Ensure all data is written */
+    guac_png_flush_data(&write_state);
     return 0;
 
 }