diff --git a/src/utils/lib.h b/src/utils/lib.h
index 906106fb8..45f7a0d13 100644
--- a/src/utils/lib.h
+++ b/src/utils/lib.h
@@ -288,6 +288,7 @@ typedef struct
 {
 	unsigned size;
 	unsigned capacity;
+	char data[];
 } VHeader_;
 
 static inline VHeader_* vec_new_(size_t element_size, size_t capacity)