diff --git a/firmware/ice40-riscv/common/utils.h b/firmware/ice40-riscv/common/utils.h
index fc898f8..03359ae 100644
--- a/firmware/ice40-riscv/common/utils.h
+++ b/firmware/ice40-riscv/common/utils.h
@@ -10,3 +10,6 @@
 #include <stdbool.h>
 
 char *hexstr(void *d, int n, bool space);
+
+void _panic(const char *file, int lineno, const char *fmt, ...);
+#define panic(fmt, ...) _panic(__FILE__, __LINE__, fmt, ##__VA_ARGS__)