diff --git a/artiq/gateware/nist_clock.py b/artiq/gateware/nist_clock.py
index dd8edaa22..b6db05efe 100644
--- a/artiq/gateware/nist_clock.py
+++ b/artiq/gateware/nist_clock.py
@@ -38,8 +38,8 @@ fmc_adapter_io = [
         Subsignal("rst", Pins("LPC:LA25_P")),
         IOStandard("LVTTL")),
 
-    ("i2c", 0,
-        Subsignal("scl", Pins("LPC:IIC_SLC")),
+    ("i2c_fmc", 0,
+        Subsignal("scl", Pins("LPC:IIC_SCL")),
         Subsignal("sda", Pins("LPC:IIC_SDA")),
         IOStandard("LVCMOS25")),
 
diff --git a/artiq/gateware/nist_qc2.py b/artiq/gateware/nist_qc2.py
index 442d66ee6..9fba61b16 100644
--- a/artiq/gateware/nist_qc2.py
+++ b/artiq/gateware/nist_qc2.py
@@ -48,7 +48,7 @@ fmc_adapter_io = [
         Subsignal("rst", Pins("LPC:LA25_P")),
         IOStandard("LVTTL")),
 
-    ("i2c", 0,
+    ("i2c_fmc", 0,
         Subsignal("scl", Pins("LPC:IIC_SCL")),
         Subsignal("sda", Pins("LPC:IIC_SDA")),
         IOStandard("LVCMOS25")),