diff --git a/src/smt/seq/seq_nielsen.cpp b/src/smt/seq/seq_nielsen.cpp
index b70629ca6..abfae8e8a 100644
--- a/src/smt/seq/seq_nielsen.cpp
+++ b/src/smt/seq/seq_nielsen.cpp
@@ -35,7 +35,6 @@ NSB review:
 #include "ast/rewriter/th_rewriter.h"
 #include "ast/rewriter/var_subst.h"
 #include "ast/rewriter/seq_skolem.h"
-#include "sat/smt/arith_solver.h"
 #include "util/statistics.h"
 #include <algorithm>
 #include <cstdlib>