diff --git a/src/ast.cpp b/src/ast.cpp
index 403ddf7..c011bd5 100644
--- a/src/ast.cpp
+++ b/src/ast.cpp
@@ -4,17 +4,14 @@
 
 namespace lily {
     type* ast_num::check(type_manager& mgr, std::shared_ptr<type_env> env) {
-        std::cout << "checking number" << std::endl;
         return mgr.require_type("Int");
     }
 
     type* ast_var::check(type_manager& mgr, std::shared_ptr<type_env> env) {
-        std::cout << "checking variable" << std::endl;
         return env->get_identifier_type(name);
     }
 
     type* ast_app::check(type_manager& mgr, std::shared_ptr<type_env> env) {
-        std::cout << "checking application" << std::endl;
         type* ltype = left->check(mgr, env);
         type* rtype = right->check(mgr, env);
 
diff --git a/src/main.cpp b/src/main.cpp
index a5d2385..d40831d 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -9,7 +9,8 @@ int main() {
                 "data Color = { Red, Black }\n"
                 "data IntList = { Nil, Cons(Int, IntList) }\n"
                 "defn other x y = { 3 }\n"
-                "defn add x y = { x + add x x }");
+                "defn add x y = { x + y }\n"
+                "defn ones = { Cons 1 ones }");
     } catch(lily::error& e) {
         std::cout << e.message << std::endl;
     }
diff --git a/src/parser.cpp b/src/parser.cpp
index f0b999d..2b2dfbe 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -279,6 +279,9 @@ namespace lily {
             base_env->set_type(pair.first, current_type);
         }
 
+        // We also want to gather all the constructor calls.
+        type_mgr.register_constructors(base_env);
+
         // Now that we have collected the functions, check their bodies.
         for(auto& pair : functions) {
             type* body_type =
diff --git a/src/type.cpp b/src/type.cpp
index d1aea8f..240b121 100644
--- a/src/type.cpp
+++ b/src/type.cpp
@@ -10,7 +10,7 @@ namespace lily {
         new_constructor->params = std::move(params);
 
         constructor* raw_ptr = new_constructor.get();
-        constructors.push_back(std::move(new_constructor));
+        constructors[name] = std::move(new_constructor);
         return raw_ptr;
     }
 
diff --git a/src/type.hpp b/src/type.hpp
index 66a0133..564a720 100644
--- a/src/type.hpp
+++ b/src/type.hpp
@@ -1,6 +1,7 @@
 #pragma once
 #include <string>
 #include <vector>
+#include <map>
 
 namespace lily {
     enum reserved_types {
@@ -34,7 +35,7 @@ namespace lily {
         };
 
         int type_id;
-        std::vector<std::unique_ptr<constructor>> constructors;
+        std::map<std::string, std::unique_ptr<constructor>> constructors;
 
         type_data(int id) : type_id(id) {}
         constructor* create_constructor(const std::string& name, std::vector<type*>&& params);
diff --git a/src/type_checker.cpp b/src/type_checker.cpp
index b73fc1e..02fcf80 100644
--- a/src/type_checker.cpp
+++ b/src/type_checker.cpp
@@ -7,7 +7,6 @@ namespace lily {
     }
 
     type* type_env::get_identifier_type(const std::string& name) {
-        std::cout << "looking up " << name << std::endl;
         if(!identifier_types.count(name)) {
             if(parent) return parent->get_identifier_type(name);
             throw error("unknown variable");
diff --git a/src/type_manager.cpp b/src/type_manager.cpp
index 92b9c58..a27326a 100644
--- a/src/type_manager.cpp
+++ b/src/type_manager.cpp
@@ -1,6 +1,8 @@
 #include "type_manager.hpp"
 #include <memory>
 #include "error.hpp"
+#include "type.hpp"
+#include "type_checker.hpp"
 
 namespace lily {
     type_manager::type_manager() {
@@ -38,4 +40,21 @@ namespace lily {
         if(!type_names.count(name)) throw error("invalid type name");
         return type_names.find(name)->second;
     }
+
+    void type_manager::register_constructors(std::shared_ptr<type_env> env) {
+        for(auto& type_ref : types) {
+            type_data* data_type = dynamic_cast<type_data*>(type_ref.get());
+            if(!data_type) continue;
+
+            for(auto& pair : data_type->constructors) {
+                size_t param_count = pair.second->params.size();
+                type* current_type = data_type;
+                for(int i = 0; i < param_count; i++) {
+                    type* param = pair.second->params[param_count - i - 1];
+                    current_type = create_type<type_func>(param, current_type);
+                }
+                env->set_type(pair.first, current_type);
+            }
+        }
+    }
 }
diff --git a/src/type_manager.hpp b/src/type_manager.hpp
index 71e406e..253525f 100644
--- a/src/type_manager.hpp
+++ b/src/type_manager.hpp
@@ -5,6 +5,8 @@
 #include "type.hpp"
 
 namespace lily {
+    class type_env;
+
     class type_manager {
         private:
             int next_id;
@@ -25,5 +27,7 @@ namespace lily {
             }
 
             type* require_type(const std::string& name) const;
+
+            void register_constructors(std::shared_ptr<type_env> env);
     };
 }