diff --git a/litex/soc/software/libc/or1k/exception.c b/litex/soc/software/libc/or1k/exception.c
index 278cd6a5b..95d96ca36 100644
--- a/litex/soc/software/libc/or1k/exception.c
+++ b/litex/soc/software/libc/or1k/exception.c
@@ -1,5 +1,6 @@
 #include <generated/csr.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <stdarg.h>
 
 void isr(void);