I am using Eclipse v4.3 (Kepler), and this is how I solved my problem.
Goto menu Help ? Install new software ? click Add.
In the popup, give any name (I named it as Eclipse ADT Plugin), and in the link's place, use https://dl-ssl.google.com/android/eclipse/
Once you click OK, you will be displayed with new packages that will be installed and old packages that will be deleted. Don't worry about these packages. Click OK.
New packages will be installed, and this should solve your problem.