diff --git a/artiq/gateware/phaser.py b/artiq/gateware/phaser.py
index d72e6c153..4673b7b90 100644
--- a/artiq/gateware/phaser.py
+++ b/artiq/gateware/phaser.py
@@ -25,16 +25,19 @@ fmc_adapter_io = [
         Subsignal("p", Pins("HPC:LA00_CC_P")),
         Subsignal("n", Pins("HPC:LA00_CC_N")),
         IOStandard("LVDS_25"),
+        Misc("DIFF_TERM=TRUE"),
     ),
     ("ad9154_sync", 0,
         Subsignal("p", Pins("HPC:LA01_CC_P")),
         Subsignal("n", Pins("HPC:LA01_CC_N")),
         IOStandard("LVDS_25"),
+        Misc("DIFF_TERM=TRUE"),
     ),
     ("ad9154_sync", 1,
         Subsignal("p", Pins("HPC:LA02_P")),
         Subsignal("n", Pins("HPC:LA02_N")),
         IOStandard("LVDS_25"),
+        Misc("DIFF_TERM=TRUE"),
     ),
     ("ad9154_jesd", 0, # AD9154's SERIND7
         Subsignal("txp", Pins("HPC:DP0_C2M_P")),