diff --git a/include/blt/gp/tree.h b/include/blt/gp/tree.h
index 2d10a1e..72c353d 100644
--- a/include/blt/gp/tree.h
+++ b/include/blt/gp/tree.h
@@ -273,60 +273,7 @@ namespace blt::gp
          *
          * This function is meant to copy into and replaces data inside the tree.
          */
-        void copy_fast(const tree_t& copy)
-        {
-            if (this == &copy)
-                return;
-
-            operations.reserve(copy.operations.size());
-
-            auto copy_it = copy.operations.begin();
-            auto op_it = operations.begin();
-
-            size_t total_op_bytes = 0;
-            size_t total_copy_bytes = 0;
-
-            for (; op_it != operations.end(); ++op_it)
-            {
-                if (copy_it == copy.operations.end())
-                    break;
-                if (copy_it->is_value())
-                {
-                    copy.handle_refcount_increment(copy_it, total_copy_bytes);
-                    total_copy_bytes += copy_it->type_size();
-                }
-                if (op_it->is_value())
-                {
-                    handle_refcount_decrement(op_it, total_op_bytes);
-                    total_op_bytes += op_it->type_size();
-                }
-                *op_it = *copy_it;
-                ++copy_it;
-            }
-            const auto op_it_cpy = op_it;
-            for (; op_it != operations.end(); ++op_it)
-            {
-                if (op_it->is_value())
-                {
-                    handle_refcount_decrement(op_it, total_op_bytes);
-                    total_op_bytes += op_it->type_size();
-                }
-            }
-            operations.erase(op_it_cpy, operations.end());
-            for (; copy_it != copy.operations.end(); ++copy_it)
-            {
-                if (copy_it->is_value())
-                {
-                    copy.handle_refcount_increment(copy_it, total_copy_bytes);
-                    total_copy_bytes += copy_it->type_size();
-                }
-                operations.emplace_back(*copy_it);
-            }
-
-            values.reserve(copy.values.stored());
-            values.reset();
-            values.insert(copy.values);
-        }
+        void copy_fast(const tree_t& copy);
 
         tree_t(tree_t&& move) = default;
 
diff --git a/src/transformers.cpp b/src/transformers.cpp
index 511ad74..1aef4a2 100644
--- a/src/transformers.cpp
+++ b/src/transformers.cpp
@@ -36,7 +36,7 @@ namespace blt::gp
 
     inline void print_mutate_stats()
     {
-        std::cerr << "Mutation statistics (Total: " << (mutate_point_counter + mutate_expression_counter + mutate_adjust_counter +
+        std::cerr << "Mutation statistics (Total: " << (mutate_point_counter + mutate_adjust_counter +
             mutate_sub_func_counter + mutate_jump_counter + mutate_copy_counter) << "):" << std::endl;
         std::cerr << "\tSuccessful Point Mutations: " << mutate_point_counter << std::endl;
         std::cerr << "\tSuccessful Expression Mutations: " << mutate_expression_counter << std::endl;
diff --git a/src/tree.cpp b/src/tree.cpp
index f45a6a7..a46856b 100644
--- a/src/tree.cpp
+++ b/src/tree.cpp
@@ -62,6 +62,62 @@ namespace blt::gp
         tree.values.pop_bytes(bytes);
     }
 
+    void tree_t::copy_fast(const tree_t& copy)
+    {
+        if (this == &copy)
+            return;
+
+        operations.reserve(copy.operations.size());
+
+        auto copy_it = copy.operations.begin();
+        auto op_it = operations.begin();
+
+        size_t total_op_bytes = 0;
+        size_t total_copy_bytes = 0;
+
+        for (; op_it != operations.end(); ++op_it)
+        {
+            if (copy_it == copy.operations.end())
+                break;
+            if (copy_it->is_value())
+            {
+                copy.handle_refcount_increment(copy_it, total_copy_bytes);
+                total_copy_bytes += copy_it->type_size();
+            }
+            if (op_it->is_value())
+            {
+                handle_refcount_decrement(op_it, total_op_bytes);
+                total_op_bytes += op_it->type_size();
+            }
+            *op_it = *copy_it;
+            ++copy_it;
+        }
+        const auto op_it_cpy = op_it;
+        for (; op_it != operations.end(); ++op_it)
+        {
+            if (op_it->is_value())
+            {
+                handle_refcount_decrement(op_it, total_op_bytes);
+                total_op_bytes += op_it->type_size();
+            }
+        }
+        operations.erase(op_it_cpy, operations.end());
+        for (; copy_it != copy.operations.end(); ++copy_it)
+        {
+            if (copy_it->is_value())
+            {
+                copy.handle_refcount_increment(copy_it, total_copy_bytes);
+                total_copy_bytes += copy_it->type_size();
+            }
+            operations.emplace_back(*copy_it);
+        }
+
+        values.reserve(copy.values.stored());
+        values.reset();
+        values.insert(copy.values);
+    }
+
+
     void tree_t::print(std::ostream& out, const bool print_literals, const bool pretty_print, const bool include_types,
                        const ptrdiff_t marked_index) const
     {