diff --git a/src/bindings/perl/hammer.i b/src/bindings/perl/hammer.i
index 6e3a133..eaf504d 100644
--- a/src/bindings/perl/hammer.i
+++ b/src/bindings/perl/hammer.i
@@ -1,6 +1,7 @@
 %module hammer;
 %begin %{
 #include <unistd.h>
+#include <stdbool.h>
 #include <stdint.h>
 %}