A report has found staff at Brisbane's Wesley Hospital were not to blame for patient deaths from legionnaire's disease.
A 60-year-old man died after an outbreak in June and it later emerged legionnaire's disease had killed another patient in 2011.
Every hospital in Queensland had its water supply tested and treated as a result.
The report by Queensland's chief health officer has found no evidence the Wesley Hospital was negligent in dealing with the disease.
Dr Jeannette Young says water testing must continue into the future.
"This is about protecting patients in our hospitals and our aged care facilities," she said.
She says the Public Health Act should be amended to make the current testing program for legionella bacteria mandatory.
Health Minister Lawrence Springborg tabled the report in Parliament today.
He has agreed to change the law, arguing the benefits of continued testing outweigh the costs.
"I don't think it's a cost issue, it's an issue of making sure the public has confidence and are safe in our hospitals," he said.
"There was no evidence of negligence or intent on the part of the Wesley Hospital resulting in harm to visitors, patients or staff.
"There were, however, administrative issues in regard to the Wesley Hospital's management of, and response to, the outbreak of legionnaire's disease.
"These deficiencies resulted in their failure to notify Queensland Health of the first positive legionella test result from the Wesley.
"Fortunately, in this case the failure had no impact on future risks to other patients, given the prompt and comprehensive actions undertaken by the Wesley Hospital."