diff --git a/gtsam/nonlinear/FixedLagSmoother.h b/gtsam/nonlinear/FixedLagSmoother.h
index f628815a4..ba17b474b 100644
--- a/gtsam/nonlinear/FixedLagSmoother.h
+++ b/gtsam/nonlinear/FixedLagSmoother.h
@@ -20,10 +20,6 @@
 // \callgraph
 #pragma once
 
-#ifdef GTSAN_BUILD_UNSTABLE
-#include <gtsam_unstable/dllexport.h>
-#endif
-
 #include <gtsam/dllexport.h>
 #include <gtsam/inference/Key.h>
 #include <gtsam/nonlinear/NonlinearFactorGraph.h>
diff --git a/gtsam_unstable/nonlinear/IncrementalFixedLagSmoother.h b/gtsam_unstable/nonlinear/IncrementalFixedLagSmoother.h
index bc1c48524..8a14d60c2 100644
--- a/gtsam_unstable/nonlinear/IncrementalFixedLagSmoother.h
+++ b/gtsam_unstable/nonlinear/IncrementalFixedLagSmoother.h
@@ -22,6 +22,7 @@
 
 #include <gtsam/nonlinear/FixedLagSmoother.h>
 #include <gtsam/nonlinear/ISAM2.h>
+#include "<gtsam_unstable/dllexport.h>"
 
 namespace gtsam {