diff --git a/README.md b/README.md
index 40060e2..2952e16 100644
--- a/README.md
+++ b/README.md
@@ -37,6 +37,7 @@ The [CWLProv white paper](https://doi.org/10.5281/zenodo.1208477) describes the
 ## Known implementations
 
 * [cwltool --provenance](https://github.com/common-workflow-language/cwltool/blob/master/CWLProv.rst) (reference implementation)
+* [cwlprov-py](https://github.com/common-workflow-language/cwlprov-py) (work in progress, command line tool)
 * [nextflow -with-prov](https://github.com/edgano/researchObject-Nextflow) (work in progress, ~ CWLProv without CWL)