diff --git a/R.gitignore b/R.gitignore
index a0fd3b34..9a1509d5 100644
--- a/R.gitignore
+++ b/R.gitignore
@@ -3,3 +3,6 @@
 
 # Example code in package build process
 *-Ex.R
+
+# R data files from past sessions
+.Rdata