diff --git a/examples/cv.pdf b/examples/cv.pdf
index 4f67d87..90daff8 100644
Binary files a/examples/cv.pdf and b/examples/cv.pdf differ
diff --git a/examples/cv.tex b/examples/cv.tex
index 15cac2b..a2201a1 100644
--- a/examples/cv.tex
+++ b/examples/cv.tex
@@ -94,7 +94,7 @@
 \input{cv/education.tex}
 \input{cv/skills.tex}
 \input{cv/experience.tex}
-%\input{cv/extracurricular.tex}
+\input{cv/extracurricular.tex}
 %\input{cv/honors.tex}
 %\input{cv/presentation.tex}
 %\input{cv/writing.tex}
diff --git a/examples/cv/extracurricular.tex b/examples/cv/extracurricular.tex
index 67599f7..6b1bd7e 100644
--- a/examples/cv/extracurricular.tex
+++ b/examples/cv/extracurricular.tex
@@ -11,71 +11,17 @@
 
 %---------------------------------------------------------
   \cventry
-    {Core Member} % Affiliation/role
-    {B10S (B1t 0n the Security, Underground hacker team)} % Organization/group
-    {S.Korea} % Location
-    {Nov. 2011 - PRESENT} % Date(s)
+    {Participant of Google Summer of Code project} % Affiliation/role
+    {CheckStyle} % Organization/group
+    {Saint-Petersburg} % Location
+    {Apr. 2017 - Jun. 2017} % Date(s)
     {
       \begin{cvitems} % Description(s) of experience/contributions/knowledge
-        \item {Gained expertise in penetration testing areas, especially targeted on web application and software.}
-        \item {Participated on a lot of hacking competition and won a good award.}
-        \item {Held several hacking competitions non-profit, just for fun.}
+        \item{Code Review}
+        \item{Analyzing of existing project's code}
+        \item{Fixing existing bugs:
+          \\ \href{https://github.com/checkstyle/checkstyle/issues?q=author\%3Aunrealwork}{\faGithubSquare\acvHeaderIconSep\@Java, ANTLR}
+        }
       \end{cvitems}
     }
-
-%---------------------------------------------------------
-  \cventry
-    {Member} % Affiliation/role
-    {WiseGuys (Hacking \& Security research group)} % Organization/group
-    {S.Korea} % Location
-    {Jun. 2012 - PRESENT} % Date(s)
-    {
-      \begin{cvitems} % Description(s) of experience/contributions/knowledge
-        \item {Gained expertise in hardware hacking areas from penetration testing on several devices including wireless router, smartphone, CCTV and set-top box.}
-        \item {Trained wannabe hacker about hacking technique from basic to advanced and ethics for white hackers by hosting annual Hacking Camp.}
-      \end{cvitems}
-    }
-
-%---------------------------------------------------------
-  \cventry
-    {Core Member \& President at 2013} % Affiliation/role
-    {PoApper (Developers' Network of POSTECH)} % Organization/group
-    {Pohang, S.Korea} % Location
-    {Jun. 2010 - PRESENT} % Date(s)
-    {
-      \begin{cvitems} % Description(s) of experience/contributions/knowledge
-        \item {Reformed the society focusing on software engineering and building network on and off campus.}
-        \item {Proposed various marketing and network activities to raise awareness.}
-      \end{cvitems}
-    }
-
-%---------------------------------------------------------
-  \cventry
-    {Member} % Affiliation/role
-    {PLUS (Laboratory for UNIX Security in POSTECH)} % Organization/group
-    {Pohang, S.Korea} % Location
-    {Sep. 2010 - Oct. 2011} % Date(s)
-    {
-      \begin{cvitems} % Description(s) of experience/contributions/knowledge
-        \item {Gained expertise in hacking \& security areas, especially about internal of operating system based on UNIX and several exploit techniques.}
-        \item {Participated on several hacking competition and won a good award.}
-        \item {Conducted periodic security checks on overall IT system as a member of POSTECH CERT.}
-        \item {Conducted penetration testing commissioned by national agency and corporation.}
-      \end{cvitems}
-    }
-
-%---------------------------------------------------------
-  \cventry
-    {Member} % Affiliation/role
-    {MSSA (Management Strategy Club of POSTECH)} % Organization/group
-    {Pohang, S.Korea} % Location
-    {Sep. 2013 - PRESENT} % Date(s)
-    {
-      \begin{cvitems} % Description(s) of experience/contributions/knowledge
-        \item {Gained knowledge about several business field like Management, Strategy, Financial and marketing from group study.}
-        \item {Gained expertise in business strategy areas and inisght for various industry from weekly industry analysis session.}
-      \end{cvitems}
-    }
-
-%---------------------------------------------------------
 \end{cventries}