diff --git a/docs/feature-support-matrix.md b/docs/feature-support-matrix.md
index 3395532e9..68c4d80cf 100644
--- a/docs/feature-support-matrix.md
+++ b/docs/feature-support-matrix.md
@@ -23,11 +23,14 @@ The matrix below reflects the canonical Council-ratified version. As outlined in
 | eip155:43114             | avalanche     | Yes         | Yes          | Yes               | Yes                  | Yes              |
 | eip155:250               | fantom        | Yes         | Yes          | Yes               | Yes                  | Yes              |
 | eip155:137               | polygon       | Yes         | Yes          | Yes               | Yes                  | Yes              |
+| eip155:10                | optimism      | Yes         | Yes          | Yes               | Yes                  | Yes              |
 | **Data Source Features** |               |             |              |                   |                      |                  |
 | ipfs.cat in mappings     |               | Yes         | Yes          | No                | No                   | No               |
 | ENS                      |               | Yes         | Yes          | No                | No                   | No               |
 | File data sources: IPFS  |               | Yes         | Yes          | No                | Yes                  | Yes              |
-| Substreams data sources  | mainnet       | Yes         | Yes          | Yes               | Yes                  | Yes              | 
+| Substreams: mainnet      |               | Yes         | Yes          | Yes               | Yes                  | Yes              | 
+| Substreams: optimism     |               | Yes         | Yes          | Yes               | Yes                  | Yes              | 
+
 
 The accepted `graph-node` version range must always be specified; it always comprises the latest available version and the one immediately preceding it. 
 The latest for the feature matrix above: