diff --git a/src/map/if/acd/ac_decomposition.hpp b/src/map/if/acd/ac_decomposition.hpp
index 3c72b792f..7cd6d9613 100644
--- a/src/map/if/acd/ac_decomposition.hpp
+++ b/src/map/if/acd/ac_decomposition.hpp
@@ -111,6 +111,12 @@ public:
 
     uint32_t late_arriving = __builtin_popcount( delay_profile );
 
+    /* relax maximum number of free set variables if a function has more variables */
+    if ( num_vars > ps.max_free_set_vars + ps.lut_size )
+    {
+      ps.max_free_set_vars = num_vars - ps.lut_size;
+    }
+
     /* return a high cost if too many late arriving variables */
     if ( late_arriving > ps.lut_size - 1 || late_arriving > ps.max_free_set_vars )
     {
@@ -1444,7 +1450,7 @@ private:
   std::vector<std::array<uint32_t, 2>> support_minimization_encodings;
 
   uint32_t num_vars;
-  ac_decomposition_params const& ps;
+  ac_decomposition_params ps;
   ac_decomposition_stats* pst;
   std::array<uint32_t, max_num_vars> permutations;
 };