diff --git a/include/xo/procedure2/ObjectPrimitives.hpp b/include/xo/procedure2/ObjectPrimitives.hpp
index 696fc29..c403dc1 100644
--- a/include/xo/procedure2/ObjectPrimitives.hpp
+++ b/include/xo/procedure2/ObjectPrimitives.hpp
@@ -40,13 +40,16 @@ namespace xo {
                                                         StringTable * stbl);
 
             /** create primitive for creating a dictionary instance **/
-            static DPrimitive_gco_2_dict_string * make_dict_lookup_pm(obj<AAllocator> mm);
+            static DPrimitive_gco_2_dict_string * make_dict_lookup_pm(obj<AAllocator> mm,
+                                                                      StringTable * stbl);
 
             /** create primitive that upserts a key,value pair into a dictionary **/
-            static DPrimitive_gco_3_dict_string_gco * make_dict_upsert_pm(obj<AAllocator> mm);
+            static DPrimitive_gco_3_dict_string_gco * make_dict_upsert_pm(obj<AAllocator> mm,
+                                                                          StringTable * stbl);
 
             /** create primitive: get fixed number of args for function **/
-            static DPrimitive_gco_1_gco * make_fn_n_args_pm(obj<AAllocator> mm);
+            static DPrimitive_gco_1_gco * make_fn_n_args_pm(obj<AAllocator> mm,
+                                                            StringTable * stbl);
         };
 
     } /*namespace scm*/
diff --git a/src/procedure2/ObjectPrimitives.cpp b/src/procedure2/ObjectPrimitives.cpp
index d52c530..4edd387 100644
--- a/src/procedure2/ObjectPrimitives.cpp
+++ b/src/procedure2/ObjectPrimitives.cpp
@@ -163,9 +163,21 @@ namespace xo {
         }
 
         DPrimitive_gco_2_dict_string *
-        ObjectPrimitives::make_dict_lookup_pm(obj<AAllocator> mm)
+        ObjectPrimitives::make_dict_lookup_pm(obj<AAllocator> mm,
+                                              StringTable * stbl)
         {
-            return DPrimitive_gco_2_dict_string::_make(mm, "dict_lookup", &xfer_dict_lookup);
+            (void)stbl;
+
+            // dict_ty: generic dictionary
+            auto dict_ty = DAtomicType::make(mm, Metatype::t_dict());
+            auto str_ty = DAtomicType::make(mm, Metatype::t_str());
+            auto any_ty = DAtomicType::make(mm, Metatype::t_any());
+            // pm_ty: dict x string -> any
+            auto pm_ty = obj<AType,DFunctionType>
+                (DFunctionType::_make(mm, any_ty, dict_ty, str_ty));
+
+            return DPrimitive_gco_2_dict_string::_make
+                (mm, "dict_lookup", pm_ty, &xfer_dict_lookup);
         }
 
         // ----- dict_upsert -----
@@ -196,9 +208,23 @@ namespace xo {
         }
 
         DPrimitive_gco_3_dict_string_gco *
-        ObjectPrimitives::make_dict_upsert_pm(obj<AAllocator> mm)
+        ObjectPrimitives::make_dict_upsert_pm(obj<AAllocator> mm,
+                                              StringTable * stbl)
         {
-            return DPrimitive_gco_3_dict_string_gco::_make(mm, "dict_upsert", &xfer_dict_upsert);
+            (void)stbl;
+
+            auto dict_ty = DAtomicType::make(mm, Metatype::t_dict());
+            auto str_ty = DAtomicType::make(mm, Metatype::t_str());
+            auto any_ty = DAtomicType::make(mm, Metatype::t_any());
+            // pm_ty: dict x string x any -> dict
+            auto pm_ty = obj<AType,DFunctionType>(DFunctionType::_make(mm,
+                                                                       dict_ty,
+                                                                       dict_ty,
+                                                                       str_ty,
+                                                                       any_ty));
+
+            return DPrimitive_gco_3_dict_string_gco::_make
+                (mm, "dict_upsert", pm_ty, &xfer_dict_upsert);
         }
 
         // ----- fn_n_args -----
@@ -220,9 +246,18 @@ namespace xo {
         }
 
         DPrimitive_gco_1_gco *
-        ObjectPrimitives::make_fn_n_args_pm(obj<AAllocator> mm)
+        ObjectPrimitives::make_fn_n_args_pm(obj<AAllocator> mm,
+                                            StringTable * stbl)
         {
-            return DPrimitive_gco_1_gco::_make(mm, "fn_n_args", &xfer_fn_n_args);
+            (void)stbl;
+
+            auto integer_ty = DAtomicType::make(mm, Metatype::t_integer());
+            auto callable_ty = DAtomicType::make(mm, Metatype::t_callable());
+            auto pm_ty = obj<AType,DFunctionType>(DFunctionType::_make(mm,
+                                                                       integer_ty,
+                                                                       callable_ty));
+
+            return DPrimitive_gco_1_gco::_make(mm, "fn_n_args", pm_ty, &xfer_fn_n_args);
         }
 
     } /*namespace scm*/
diff --git a/src/procedure2/procedure2_register_primitives.cpp b/src/procedure2/procedure2_register_primitives.cpp
index eed4cf5..29f3be1 100644
--- a/src/procedure2/procedure2_register_primitives.cpp
+++ b/src/procedure2/procedure2_register_primitives.cpp
@@ -62,13 +62,13 @@ namespace xo {
 
             bool ok = true;
 
-            ok = ok & install_aux(sink, ObjectPrimitives::make_cwd_pm(mm, stbl), flags);
-            ok = ok & install_aux(sink, ObjectPrimitives::make_nth_pm(mm, stbl), flags);
-            ok = ok & install_aux(sink, ObjectPrimitives::make_cons_pm(mm, stbl), flags);
-            ok = ok & install_aux(sink, ObjectPrimitives::make_dict_make_pm(mm, stbl), flags);
-            ok = ok & install_aux(sink, ObjectPrimitives::make_dict_lookup_pm(mm), flags);
-            ok = ok & install_aux(sink, ObjectPrimitives::make_dict_upsert_pm(mm), flags);
-            ok = ok & install_aux(sink, ObjectPrimitives::make_fn_n_args_pm(mm), flags);
+            ok = ok & install_aux(sink, ObjectPrimitives::make_cwd_pm         (mm, stbl), flags);
+            ok = ok & install_aux(sink, ObjectPrimitives::make_nth_pm         (mm, stbl), flags);
+            ok = ok & install_aux(sink, ObjectPrimitives::make_cons_pm        (mm, stbl), flags);
+            ok = ok & install_aux(sink, ObjectPrimitives::make_dict_make_pm   (mm, stbl), flags);
+            ok = ok & install_aux(sink, ObjectPrimitives::make_dict_lookup_pm (mm, stbl), flags);
+            ok = ok & install_aux(sink, ObjectPrimitives::make_dict_upsert_pm (mm, stbl), flags);
+            ok = ok & install_aux(sink, ObjectPrimitives::make_fn_n_args_pm   (mm, stbl), flags);
 
             return ok;
         }