diff --git a/spec/test_macros.c b/spec/test_macros.c
index 6d0c4ae..a26a1d2 100644
--- a/spec/test_macros.c
+++ b/spec/test_macros.c
@@ -3,6 +3,7 @@
 #include <string.h>
 #include <assert.h>
 #include <stddef.h>
+#include <stdbool.h>
 
 static p_context_t * context;
 size_t n_tokens;