diff --git a/src/bin/common_output.cc b/src/bin/common_output.cc
index 6ffa23a4f..91ed7c127 100644
--- a/src/bin/common_output.cc
+++ b/src/bin/common_output.cc
@@ -21,6 +21,7 @@
 
 #include "common_output.hh"
 #include <iostream>
+#include "ltlvisit/tostring.hh"
 
 #define OPT_SPOT 1
 
diff --git a/src/bin/common_output.hh b/src/bin/common_output.hh
index fec869ad1..bfe76b017 100644
--- a/src/bin/common_output.hh
+++ b/src/bin/common_output.hh
@@ -27,7 +27,7 @@
 #endif
 
 #include <argp.h>
-#include "ltlvisit/tostring.hh"
+#include "ltlast/formula.hh"
 
 enum output_format_t { spot_output, spin_output, utf8_output };
 extern output_format_t output_format;