diff --git a/gtsam/discrete/SignatureParser.h b/gtsam/discrete/SignatureParser.h
index e005da14a..fec3b9af2 100644
--- a/gtsam/discrete/SignatureParser.h
+++ b/gtsam/discrete/SignatureParser.h
@@ -21,6 +21,7 @@
 #include <optional>
 #include <string>
 #include <vector>
+#include <gtsam/dllexport.h>
 
 namespace gtsam {
 /**