diff --git a/artiq/firmware/satman/lib.rs b/artiq/firmware/satman/lib.rs
index 4650eab6c..80c8b7607 100644
--- a/artiq/firmware/satman/lib.rs
+++ b/artiq/firmware/satman/lib.rs
@@ -1,13 +1,13 @@
-#![feature(compiler_builtins_lib)]
+#![feature(compiler_builtins_lib, lang_items)]
 #![no_std]
 
 extern crate compiler_builtins;
 extern crate alloc_artiq;
-#[macro_use]
 extern crate std_artiq as std;
 #[macro_use]
 extern crate log;
 extern crate logger_artiq;
+#[macro_use]
 extern crate board;
 extern crate drtioaux;
 
@@ -148,6 +148,13 @@ pub extern fn abort() {
     panic!("aborted")
 }
 
+#[no_mangle]
+#[lang = "panic_fmt"]
+pub extern fn panic_fmt(args: core::fmt::Arguments, file: &'static str, line: u32) -> ! {
+    println!("panic at {}:{}: {}", file, line, args);
+    loop {}
+}
+
 // Allow linking with crates that are built as -Cpanic=unwind even if we use -Cpanic=abort.
 // This is never called.
 #[allow(non_snake_case)]