Apply Conditional Formatting to Relative Range

Hello,

I have applied conditional formatting to a group of cells A1:C3 based on the value of A1, so that if A1 = x then A1:C3 is highlighted. However I need to repeat this group of 9 cells multiple times down the spreadsheet; for example, I need A4:C6 to be the same, A7:C9, etc. The condition formula uses relative references (so that when I copy the group and paste, the condition is A4 = x, A7 = x, etc.). However I can't seem to get the "Applies to" range to stay relative. When I copy A1:C3 down, the new CF rule evaluates A4 as it should but still applies the format to A1:C3 and not A4:C6. Is there any way to make the "Applies to" relative, or do I actually have to manually change the range for each group?

Thank you!