diff --git a/.gitignore b/.gitignore
index a107f43f..f6c0392d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,23 +1,24 @@
 # ignore compiled byte code
 target
 
 # ignore output files from testing
 output*
 
 # ignore standard Eclipse files
 .project
 .classpath
 .settings
 .checkstyle
 
 # ignore standard IntelliJ files
 .idea/
 *.iml
+*.ipr
 *.iws
 
 # ignore standard Vim and Emacs temp files
 *.swp
 *~
 
 # ignore standard Mac OS X files/dirs
 .DS_Store