diff --git a/src/nf/nf_keras_submodule.f90 b/src/nf/nf_keras_submodule.f90
index 8f773b2b..b97c12da 100644
--- a/src/nf/nf_keras_submodule.f90
+++ b/src/nf/nf_keras_submodule.f90
@@ -65,6 +65,9 @@ module function get_keras_h5_layers(filename) result(res)
 
     end do layers
 
+    ! free the memory:
+    call json % destroy(model_config_json)
+
   end function get_keras_h5_layers
 
 end submodule nf_keras_submodule