diff --git a/firmware/stub/tpm_lite_stub.c b/firmware/stub/tpm_lite_stub.c
index 7d3e5d2..1f31c69 100644
--- a/firmware/stub/tpm_lite_stub.c
+++ b/firmware/stub/tpm_lite_stub.c
@@ -6,6 +6,7 @@
  * equivalents.
  */
 
+#include <assert.h>
 #include <stdint.h>
 #include <errno.h>
 #include <fcntl.h>