diff --git a/xgraph/README b/xgraph/README
index 87a39db62..f6c79de88 100644
--- a/xgraph/README
+++ b/xgraph/README
@@ -10,7 +10,7 @@ Welcome to the VINT release of xgraph.
 Xgraph is an X-Windows application that includes:
 
   - interactive plotting and graphing, by David Harrison of UC Berkeley
-  - animation and deritives, added by Paul Walker of NCSA
+  - animation and derivatives, added by Paul Walker of NCSA
   - portability and bug fixes, by the VINT project