private String getMaximum(FacesContext context, boolean isIntegral, InputNumber component) {
        String maximum = component.getMaxValue();
        if (isIntegral && NegativeClientValidationConstraint.MAX_VALUE.equals(maximum)) {
            maximum = "0";
        }

        if (maximum == null) {
            maximum = determineMaximumFromType(context, component);
        }

        return formatForPlugin(maximum);
    }
If using @Negative annotation and this is an Integer default to 0 instead of -0.0001.
@param context faces context
@param isIntegral flag whether the (expected) value is integral
@param component the component
@return the maximum value of the component
primefaces/src/main/java/org/primefaces/component/inputnumber/InputNumberRenderer.java