Add another needed header
diff --git a/src/bc/program.c b/src/bc/program.c
index 771e033..a34c8b0 100644
--- a/src/bc/program.c
+++ b/src/bc/program.c
@@ -20,6 +20,7 @@
  *
  */
 
+#include <assert.h>
 #include <errno.h>
 #include <stdint.h>
 #include <stdlib.h>