diff --git a/tools/bifcl/builtin-func.y b/tools/bifcl/builtin-func.y
index 453b300eb1..64b8899164 100644
--- a/tools/bifcl/builtin-func.y
+++ b/tools/bifcl/builtin-func.y
@@ -1,4 +1,5 @@
 %{
+#include <cinttypes>
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>