diff --git a/artiq/firmware/runtime/main.rs b/artiq/firmware/runtime/main.rs
index 45e856526..21d0edf85 100644
--- a/artiq/firmware/runtime/main.rs
+++ b/artiq/firmware/runtime/main.rs
@@ -89,8 +89,8 @@ fn startup() {
 
     #[cfg(has_i2c)]
     board_artiq::i2c::init();
-    #[cfg(si5324_free_running)]
-    setup_si5324_free_running();
+    #[cfg(si5324_as_synthesizer)]
+    setup_si5324_as_synthesizer();
     #[cfg(has_hmc830_7043)]
     board_artiq::hmc830_7043::init().expect("cannot initialize HMC830/7043");
     #[cfg(has_ad9154)]
@@ -107,8 +107,8 @@ fn startup() {
     }
 }
 
-#[cfg(si5324_free_running)]
-fn setup_si5324_free_running()
+#[cfg(si5324_as_synthesizer)]
+fn setup_si5324_as_synthesizer()
 {
     // 125MHz output, from 100MHz CLKIN2 reference, 9 Hz
     #[cfg(all(rtio_frequency = "125.0", si5324_ext_ref))]
diff --git a/artiq/gateware/targets/kasli.py b/artiq/gateware/targets/kasli.py
index 72b147064..6ef5c610e 100755
--- a/artiq/gateware/targets/kasli.py
+++ b/artiq/gateware/targets/kasli.py
@@ -229,7 +229,7 @@ class Opticlock(_StandaloneBase):
     def __init__(self, **kwargs):
         _StandaloneBase.__init__(self, **kwargs)
 
-        self.config["SI5324_FREE_RUNNING"] = None
+        self.config["SI5324_AS_SYNTHESIZER"] = None
         self.config["SI5324_EXT_REF"] = None
         self.config["RTIO_FREQUENCY"] = "125.0"
 
@@ -323,7 +323,7 @@ class Master(MiniSoC, AMPSoC):
         self.config["I2C_BUS_COUNT"] = 1
         self.config["HAS_SI5324"] = None
         self.config["SI5324_SOFT_RESET"] = None
-        self.config["SI5324_FREE_RUNNING"] = None
+        self.config["SI5324_AS_SYNTHESIZER"] = None
         self.config["RTIO_FREQUENCY"] = str(rtio_clk_freq/1e6)
 
         self.comb += platform.request("sfp_ctl", 2).tx_disable.eq(0)
diff --git a/artiq/gateware/targets/sayma_amc.py b/artiq/gateware/targets/sayma_amc.py
index b25a924cb..eaa1232ac 100755
--- a/artiq/gateware/targets/sayma_amc.py
+++ b/artiq/gateware/targets/sayma_amc.py
@@ -292,7 +292,7 @@ class Master(MiniSoC, AMPSoC):
         self.csr_devices.append("i2c")
         self.config["I2C_BUS_COUNT"] = 1
         self.config["HAS_SI5324"] = None
-        self.config["SI5324_FREE_RUNNING"] = None
+        self.config["SI5324_AS_SYNTHESIZER"] = None
 
         self.comb += platform.request("sfp_tx_disable", 0).eq(0)
         self.submodules.transceiver = gth_ultrascale.GTH(