diff --git a/library/init/lean/compiler/ir/emitc.lean b/library/init/lean/compiler/ir/emitc.lean
index 4f288fdf66..4df6e12cb7 100644
--- a/library/init/lean/compiler/ir/emitc.lean
+++ b/library/init/lean/compiler/ir/emitc.lean
@@ -349,7 +349,7 @@ else
   emit offset
 
 def emitUSet (x : VarId) (n : Nat) (y : VarId) : M Unit :=
-do emit "lean_ctor_set_usize("; emit x; emit ", "; emitOffset n 0; emit ", "; emit y; emitLn ");"
+do emit "lean_ctor_set_usize("; emit x; emit ", "; emit n; emit ", "; emit y; emitLn ");"
 
 def emitSSet (x : VarId) (n : Nat) (offset : Nat) (y : VarId) (t : IRType) : M Unit :=
 do
diff --git a/library/init/lean/compiler/ir/emitcpp.lean b/library/init/lean/compiler/ir/emitcpp.lean
index 9bea518207..8da6bf8930 100644
--- a/library/init/lean/compiler/ir/emitcpp.lean
+++ b/library/init/lean/compiler/ir/emitcpp.lean
@@ -359,10 +359,18 @@ else
   emit offset
 
 def emitUSet (x : VarId) (n : Nat) (y : VarId) : M Unit :=
-do emit "lean::cnstr_set_scalar("; emit x; emit ", "; emitOffset n 0; emit ", "; emit y; emitLn ");"
+do emit "lean::cnstr_set_usize("; emit x; emit ", "; emit n; emit ", "; emit y; emitLn ");"
 
-def emitSSet (x : VarId) (n : Nat) (offset : Nat) (y : VarId) : M Unit :=
-do emit "lean::cnstr_set_scalar("; emit x; emit ", "; emitOffset n offset; emit ", "; emit y; emitLn ");"
+def emitSSet (x : VarId) (n : Nat) (offset : Nat) (y : VarId) (t : IRType) : M Unit :=
+do
+match t with
+| IRType.float  => throw "floats are not supported yet"
+| IRType.uint8  => emit "lean::cnstr_set_uint8"
+| IRType.uint16 => emit "lean::cnstr_set_uint16"
+| IRType.uint32 => emit "lean::cnstr_set_uint32"
+| IRType.uint64 => emit "lean::cnstr_set_uint64"
+| _             => throw "invalid instruction";
+emit "("; emit x; emit ", "; emitOffset n offset; emit ", "; emit y; emitLn ");"
 
 def emitJmp (j : JoinPointId) (xs : Array Arg) : M Unit :=
 do
@@ -431,10 +439,18 @@ def emitProj (z : VarId) (i : Nat) (x : VarId) : M Unit :=
 do emitLhs z; emit "lean::cnstr_get("; emit x; emit ", "; emit i; emitLn ");"
 
 def emitUProj (z : VarId) (i : Nat) (x : VarId) : M Unit :=
-do emitLhs z; emit "lean::cnstr_get_scalar<usize>("; emit x; emit ", sizeof(void*)*"; emit i; emitLn ");"
+do emitLhs z; emit "lean::cnstr_get_usize("; emit x; emit ", "; emit i; emitLn ");"
 
 def emitSProj (z : VarId) (t : IRType) (n offset : Nat) (x : VarId) : M Unit :=
-do emitLhs z; emit "lean::cnstr_get_scalar<"; emit (toCppType t); emit ">("; emit x; emit ", "; emitOffset n offset; emitLn ");"
+do emitLhs z;
+match t with
+| IRType.float  => throw "floats are not supported yet"
+| IRType.uint8  => emit "lean::cnstr_get_uint8"
+| IRType.uint16 => emit "lean::cnstr_get_uint16"
+| IRType.uint32 => emit "lean::cnstr_get_uint32"
+| IRType.uint64 => emit "lean::cnstr_get_uint64"
+| _             => throw "invalid instruction";
+emit "("; emit x; emit ", "; emitOffset n offset; emitLn ");"
 
 def toStringArgs (ys : Array Arg) : List String :=
 ys.toList.map argToCppString
@@ -619,7 +635,7 @@ partial def emitBlock (emitBody : FnBody → M Unit) : FnBody → M Unit
 | FnBody.setTag x i b      => emitSetTag x i *> emitBlock b
 | FnBody.set x i y b       => emitSet x i y *> emitBlock b
 | FnBody.uset x i y b      => emitUSet x i y *> emitBlock b
-| FnBody.sset x i o y _ b  => emitSSet x i o y *> emitBlock b
+| FnBody.sset x i o y t b  => emitSSet x i o y t *> emitBlock b
 | FnBody.mdata _ b         => emitBlock b
 | FnBody.ret x             => emit "return " *> emitArg x *> emitLn ";"
 | FnBody.case _ x alts     => emitCase emitBody x alts
diff --git a/src/runtime/object.h b/src/runtime/object.h
index 85a81d6ffd..01fa9cb8b2 100644
--- a/src/runtime/object.h
+++ b/src/runtime/object.h
@@ -581,12 +581,42 @@ inline void cnstr_release(u_obj_arg o, unsigned i) {
     dec(*field_ptr);
     *field_ptr = box(0);
 }
+inline usize cnstr_get_usize(b_obj_arg o, unsigned i) {
+    return obj_data<usize>(o, sizeof(constructor_object) + i*sizeof(void*));
+}
+inline void cnstr_set_usize(b_obj_arg o, unsigned i, usize v) {
+    obj_set_data(o, sizeof(constructor_object) + i*sizeof(void*), v);
+}
 /* Access scalar data at the given offset. */
-template<typename T> inline T cnstr_get_scalar(b_obj_arg o, size_t offset) {
+inline uint8 cnstr_get_uint8(b_obj_arg o, unsigned offset) {
+    return obj_data<uint8>(o, sizeof(constructor_object) + offset);
+}
+inline uint16 cnstr_get_uint16(b_obj_arg o, unsigned offset) {
+    return obj_data<uint16>(o, sizeof(constructor_object) + offset);
+}
+inline uint32 cnstr_get_uint32(b_obj_arg o, unsigned offset) {
+    return obj_data<uint32>(o, sizeof(constructor_object) + offset);
+}
+inline uint64 cnstr_get_uint64(b_obj_arg o, unsigned offset) {
+    return obj_data<uint32>(o, sizeof(constructor_object) + offset);
+}
+inline void cnstr_set_uint8(b_obj_arg o, unsigned offset, uint8 v) {
+    obj_set_data(o, sizeof(constructor_object) + offset, v);
+}
+inline void cnstr_set_uint16(b_obj_arg o, unsigned offset, uint16 v) {
+    obj_set_data(o, sizeof(constructor_object) + offset, v);
+}
+inline void cnstr_set_uint32(b_obj_arg o, unsigned offset, uint32 v) {
+    obj_set_data(o, sizeof(constructor_object) + offset, v);
+}
+inline void cnstr_set_uint64(b_obj_arg o, unsigned offset, uint64 v) {
+    obj_set_data(o, sizeof(constructor_object) + offset, v);
+}
+template<typename T> inline T cnstr_get_scalar(b_obj_arg o, unsigned offset) {
     return obj_data<T>(o, sizeof(constructor_object) + offset);
 }
-template<typename T> inline void cnstr_set_scalar(b_obj_arg o, unsigned i, T v) {
-    obj_set_data(o, sizeof(constructor_object) + i, v);
+template<typename T> inline void cnstr_set_scalar(b_obj_arg o, unsigned offset, T v) {
+    obj_set_data(o, sizeof(constructor_object) + offset, v);
 }
 
 inline unsigned obj_tag(b_obj_arg o) { if (is_scalar(o)) return unbox(o); else return cnstr_tag(o); }