FFMPEG concat audio pause

im trying to concat 3 MP3s into one output.mp3

ffmpeg -y -i concat:"1.mp3|2.mp3|3.mp3" -c copy output.mp3

The problem is that the concat isn't perfect, it leaves some blank spots in the output track. Looking inside output.mp3 with Audacity we can see:

http://ift.tt/1wG1xNb

Is there some functionality from FFMPEG that i can use to fix this?