diff --git a/datasources.tsv b/datasources.tsv
index 75ddec5..329ea0e 100644
--- a/datasources.tsv
+++ b/datasources.tsv
@@ -8,7 +8,7 @@ BIND	Bi	http://www.bind.ca/	http://www.bind.ca/Action?identifier=bindid&idsearch
 BioCyc	Bc	https://biocyc.org	https://biocyc.org/getid?id=$id	ECOLI:CYT-D-UBIOX-CPLX	gene		1	urn:miriam:biocyc	^\w+\:[A-Za-z0-9-]+$	BioCyc		biocyc	gene
 BioGrid	Bg	https://thebiogrid.org/	https://thebiogrid.org/$id	31623	interaction		1	urn:miriam:biogrid	^\d+$	BioGRID		biogrid	interaction
 BioModels Database	Bm	https://www.ebi.ac.uk/biomodels/	https://www.ebi.ac.uk/biomodels/$id	BIOMD0000000048	pathway		1	urn:miriam:biomodels.db	^((BIOMD|MODEL)\d{10})|(BMID\d{12})$	BioModels Database		biomodels.db	pathway
-BioSystems	Bs	http://www.ncbi.nlm.nih.gov/biosystems/	http://www.ncbi.nlm.nih.gov/biosystems/$id	1	pathway		1	urn:miriam:biosystems	^\d+$	BioSystems		biosystems	pathway
+BioSystems	Bs	https://www.ncbi.nlm.nih.gov/Structure/biosystems/docs/biosystems_about.html	https://pubchem.ncbi.nlm.nih.gov/pathway/BSID:$id	1	pathway		1	urn:miriam:biosystems	^\d+$	BioSystems		biosystems	pathway
 BRENDA	Br	https://www.brenda-enzymes.org/	https://www.brenda-enzymes.org/enzyme.php?ecno=$id	1.1.1.1	protein		1	urn:miriam:brenda	^((\d+\.-\.-\.-)|(\d+\.\d+\.-\.-)|(\d+\.\d+\.\d+\.-)|(\d+\.\d+\.\d+\.\d+))$	BRENDA		brenda	protein
 BRENDA Ligands	Brl	https://www.brenda-enzymes.org/	https://www.brenda-enzymes.de/ligand.php?brenda_ligand_id=$id	278	metabolite		1	Brl	^\d+$	BRENDA Ligands		brenda.ligand	metabolite
 CAS	Ca	https://commonchemistry.cas.org/	https://commonchemistry.cas.org/detail?cas_rn=$id	50-00-0	metabolite		1	urn:miriam:cas	^\d{1,7}\-\d{2}\-\d$	CAS	P231	cas	metabolite