diff --git a/fpga/generator/mmcm.tcl b/fpga/generator/mmcm.tcl
index de4a1a1d0..f5a7da06f 100644
--- a/fpga/generator/mmcm.tcl
+++ b/fpga/generator/mmcm.tcl
@@ -1,5 +1,6 @@
 set partNumber $::env(XILINX_PART)
 set boardName  $::env(XILINX_BOARD)
+set SYSTEMCLOCK $::env(SYSTEMCLOCK)
 
 set ipName mmcm
 
@@ -15,7 +16,7 @@ set_property -dict [list CONFIG.PRIM_IN_FREQ {100.000} \
                         CONFIG.CLKOUT4_USED {true} \
                         CONFIG.CLKOUT1_REQUESTED_OUT_FREQ {166.66667} \
                         CONFIG.CLKOUT2_REQUESTED_OUT_FREQ {200} \
-                        CONFIG.CLKOUT3_REQUESTED_OUT_FREQ {25} \
+                        CONFIG.CLKOUT3_REQUESTED_OUT_FREQ {$SYSTEMCLOCK} \
                         CONFIG.CLKOUT4_REQUESTED_OUT_FREQ {25} \
                         CONFIG.CLKIN1_JITTER_PS {10.0} \
                        ] [get_ips $ipName]