diff --git a/gtsam/basis/Chebyshev2.cpp b/gtsam/basis/Chebyshev2.cpp
index 71c3db7f06..df7bf5f192 100644
--- a/gtsam/basis/Chebyshev2.cpp
+++ b/gtsam/basis/Chebyshev2.cpp
@@ -17,6 +17,7 @@
  */
 
 #include <gtsam/basis/Chebyshev2.h>
+#include <cassert>
 
 namespace gtsam {