diff --git a/src/cbmc/cbmc_solvers.cpp b/src/cbmc/cbmc_solvers.cpp
index 825f1b855de..557bf1ca3b7 100644
--- a/src/cbmc/cbmc_solvers.cpp
+++ b/src/cbmc/cbmc_solvers.cpp
@@ -174,7 +174,7 @@ std::unique_ptr<cbmc_solverst::solvert> cbmc_solverst::get_string_refinement()
   auto prop=util_make_unique<satcheck_no_simplifiert>();
   prop->set_message_handler(get_message_handler());
   info.prop=prop.get();
-  info.refinement_bound=MAX_NB_REFINEMENT;
+  info.refinement_bound=DEFAULT_MAX_NB_REFINEMENT;
   info.ui=ui;
   if(options.get_bool_option("string-max-length"))
     info.string_max_length=options.get_signed_int_option("string-max-length");
diff --git a/src/solvers/refinement/string_refinement.h b/src/solvers/refinement/string_refinement.h
index 17149166e2a..2b6e5524915 100644
--- a/src/solvers/refinement/string_refinement.h
+++ b/src/solvers/refinement/string_refinement.h
@@ -28,7 +28,7 @@ Author: Alberto Griggio, alberto.griggio@gmail.com
 #include <solvers/refinement/string_constraint_generator.h>
 #include <solvers/refinement/string_refinement_invariant.h>
 
-#define MAX_NB_REFINEMENT 100
+#define DEFAULT_MAX_NB_REFINEMENT std::numeric_limits<size_t>::max()
 #define CHARACTER_FOR_UNKNOWN '?'
 
 struct index_set_pairt