diff --git a/R.gitignore b/R.gitignore
index 49037a0..8eff68f 100644
--- a/R.gitignore
+++ b/R.gitignore
@@ -1,16 +1,19 @@
 # History files
 .Rhistory
 .Rapp.history
 
+# Session Data files
+.RData
+
 # Example code in package build process
 *-Ex.R
 
 # RStudio files
 .Rproj.user/
 
 # produced vignettes
 vignettes/*.html
 vignettes/*.pdf
 
 # OAuth2 token, see https://github.com/hadley/httr/releases/tag/v0.3
 .httr-oauth