diff --git a/src/runtime/src/i2c.rs b/src/runtime/src/i2c.rs
index c6ba83d6..d0903019 100644
--- a/src/runtime/src/i2c.rs
+++ b/src/runtime/src/i2c.rs
@@ -1,68 +1,101 @@
 use libboard_zynq;
 
-use crate::artiq_raise;
+#[cfg(feature = "target_zc706")]
+mod i2c {
+    use crate::artiq_raise;
 
-static mut I2C_BUS: Option<libboard_zynq::i2c::I2c> = None;
+    static mut I2C_BUS: Option<libboard_zynq::i2c::I2c> = None;
 
-pub extern fn start(busno: i32) {
-    if busno > 0 {
-        artiq_raise!("I2CError", "I2C bus could not be accessed");
-    }
-    unsafe {
-        if (&mut I2C_BUS).as_mut().unwrap().start().is_err() {
-            artiq_raise!("I2CError", "I2C start failed");
+    pub extern fn start(busno: i32) {
+        if busno > 0 {
+            artiq_raise!("I2CError", "I2C bus could not be accessed");
+        }
+        unsafe {
+            if (&mut I2C_BUS).as_mut().unwrap().start().is_err() {
+                artiq_raise!("I2CError", "I2C start failed");
+            }
         }
     }
-}
 
-pub extern fn restart(busno: i32) {
-    if busno > 0 {
-        artiq_raise!("I2CError", "I2C bus could not be accessed");
-    }
-    unsafe {
-        if (&mut I2C_BUS).as_mut().unwrap().restart().is_err() {
-            artiq_raise!("I2CError", "I2C restart failed");
+    pub extern fn restart(busno: i32) {
+        if busno > 0 {
+            artiq_raise!("I2CError", "I2C bus could not be accessed");
+        }
+        unsafe {
+            if (&mut I2C_BUS).as_mut().unwrap().restart().is_err() {
+                artiq_raise!("I2CError", "I2C restart failed");
+            }
         }
     }
-}
 
-pub extern fn stop(busno: i32) {
-    if busno > 0 {
-        artiq_raise!("I2CError", "I2C bus could not be accessed");
-    }
-    unsafe {
-        if (&mut I2C_BUS).as_mut().unwrap().stop().is_err() {
-            artiq_raise!("I2CError", "I2C stop failed");
+    pub extern fn stop(busno: i32) {
+        if busno > 0 {
+            artiq_raise!("I2CError", "I2C bus could not be accessed");
+        }
+        unsafe {
+            if (&mut I2C_BUS).as_mut().unwrap().stop().is_err() {
+                artiq_raise!("I2CError", "I2C stop failed");
+            }
         }
     }
-}
 
-pub extern fn write(busno: i32, data: i32) -> bool {
-    if busno > 0 {
-        artiq_raise!("I2CError", "I2C bus could not be accessed");
-    }
-    unsafe {
-        match (&mut I2C_BUS).as_mut().unwrap().write(data as u8) {
-            Ok(r) => r,
-            Err(_) => artiq_raise!("I2CError", "I2C write failed"),
+    pub extern fn write(busno: i32, data: i32) -> bool {
+        if busno > 0 {
+            artiq_raise!("I2CError", "I2C bus could not be accessed");
+        }
+        unsafe {
+            match (&mut I2C_BUS).as_mut().unwrap().write(data as u8) {
+                Ok(r) => r,
+                Err(_) => artiq_raise!("I2CError", "I2C write failed"),
+            }
         }
     }
-}
 
-pub extern fn read(busno: i32, ack: bool) -> i32 {
-    if busno > 0 {
-        artiq_raise!("I2CError", "I2C bus could not be accessed");
-    }
-    unsafe {
-        match (&mut I2C_BUS).as_mut().unwrap().read(ack) {
-            Ok(r) => r as i32,
-            Err(_) => artiq_raise!("I2CError", "I2C read failed"),
+    pub extern fn read(busno: i32, ack: bool) -> i32 {
+        if busno > 0 {
+            artiq_raise!("I2CError", "I2C bus could not be accessed");
+        }
+        unsafe {
+            match (&mut I2C_BUS).as_mut().unwrap().read(ack) {
+                Ok(r) => r as i32,
+                Err(_) => artiq_raise!("I2CError", "I2C read failed"),
+            }
         }
     }
+
+    pub fn init() {
+        let mut i2c = libboard_zynq::i2c::I2c::i2c0();
+        i2c.init().expect("I2C bus initialization failed");
+        unsafe { I2C_BUS = Some(i2c) };
+    }
 }
 
-pub fn init() {
-    let mut i2c = libboard_zynq::i2c::I2c::i2c0();
-    i2c.init().expect("I2C bus initialization failed");
-    unsafe { I2C_BUS = Some(i2c) };
+#[cfg(not(feature = "target_zc706"))]
+mod i2c {
+    use crate::artiq_raise;
+
+    pub extern fn start(_busno: i32) {
+        artiq_raise!("I2CError", "No I2C bus");
+    }
+
+    pub extern fn restart(_busno: i32) {
+        artiq_raise!("I2CError", "No I2C bus");
+    }
+
+    pub extern fn stop(_busno: i32) {
+        artiq_raise!("I2CError", "No I2C bus");
+    }
+
+    pub extern fn write(_busno: i32, _data: i32) -> bool {
+        artiq_raise!("I2CError", "No I2C bus");
+    }
+
+    pub extern fn read(_busno: i32, _ack: bool) -> i32 {
+        artiq_raise!("I2CError", "No I2C bus");
+    }
+
+    pub fn init() {
+    }
 }
+
+pub use i2c::*;