diff --git a/README.md b/README.md
index fbaf87f..6262797 100644
--- a/README.md
+++ b/README.md
@@ -60,7 +60,7 @@ To get a list of variable names in a MAT file:
 
 ```julia
 file = matopen("matfile.mat")
-varnames = names(file)
+varnames = keys(file)
 close(file)
 ```