diff --git a/README.md b/README.md
index b930631d..d857cc01 100644
--- a/README.md
+++ b/README.md
@@ -78,6 +78,7 @@ Spike supports the following RISC-V ISA features:
   - Zicond extension, v1.0
   - Zilsd extension, v1.0
   - Zclsd extension, v1.0
+  - Zimop extension, v1.0
 
 Versioning and APIs
 -------------------