warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] in COBOL

I recently installed Open-COBOL in Ubuntu. I wrote a program helloworld.cbl and compiled it using command:

cobc -free -x -o helloworld helloworld.cbl

After compiling the code, I got a bunch of warnings all of which looks like:

warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]

Solution:
To get rid of the warnings, compile the code using command:
     cobc -free -x -O -o helloworld helloworld.cbl