Methods for making olefin polymerization catalysts and methods for making polymers using the catalysts are provided. The method for making the catalyst can include combining one or more supports with one or more magnesium-containing compounds under reaction conditions to form a first reacted product. One or more chlorinating compounds selected from the group consisting of aluminum alkyl chlorides and chloro substituted silanes can be combined with the first reacted product under reaction conditions to form a second reacted product. One or more titanium-containing compounds selected from the group consisting of titanium alkoxides and titanium halides can be combined with the second reacted product under reaction conditions to form a catalyst.