The resistance state of a memristor in a crossbar array is determined. For instance, a combined reference-sneak current is determined based on a reference voltage, a sense voltage, a non-access voltage, and a voltage applied to a target row line, and a combined read-sneak current is determined based on a read voltage, a sense voltage, a non-access voltage, and a voltage applied to a reference row line. The resistance state of a target memristor is then determined based on the combined reference-sneak current and the combined read-sneak current.