diff --git a/include/xo/reader/expect_type_xs.hpp b/include/xo/reader/expect_type_xs.hpp
index 86e5adf7..1a388f54 100644
--- a/include/xo/reader/expect_type_xs.hpp
+++ b/include/xo/reader/expect_type_xs.hpp
@@ -16,7 +16,7 @@ namespace xo {
         public:
             expect_type_xs();
 
-            static void start(exprstatestack * p_stack);
+            static void start(parserstatemachine * p_stack);
 
             virtual void on_symbol_token(const token_type & tk,
                                          parserstatemachine * p_psm) override;
diff --git a/src/reader/define_xs.cpp b/src/reader/define_xs.cpp
index 4a21a0d7..04c37c5b 100644
--- a/src/reader/define_xs.cpp
+++ b/src/reader/define_xs.cpp
@@ -112,12 +112,10 @@ namespace xo {
 
             //constexpr const char * self_name = "define_xs::on_colon_token";
 
-            auto p_stack = p_psm->p_stack_;
-
             if (this->defxs_type_ == defexprstatetype::def_2) {
                 this->defxs_type_ = defexprstatetype::def_3;
 
-                expect_type_xs::start(p_stack);
+                expect_type_xs::start(p_psm);
             } else {
                 exprstate::on_colon_token(tk, p_psm);
             }
diff --git a/src/reader/expect_formal_xs.cpp b/src/reader/expect_formal_xs.cpp
index e60b77b0..28e19ce4 100644
--- a/src/reader/expect_formal_xs.cpp
+++ b/src/reader/expect_formal_xs.cpp
@@ -64,11 +64,9 @@ namespace xo {
         expect_formal_xs::on_colon_token(const token_type & tk,
                                          parserstatemachine * p_psm)
         {
-            auto p_stack = p_psm->p_stack_;
-
             if (this->formalxs_type_ == formalstatetype::formal_1) {
                 this->formalxs_type_ = formalstatetype::formal_2;
-                expect_type_xs::start(p_stack);
+                expect_type_xs::start(p_psm);
                 /* control reenters via expect_formal_xs::on_typedescr() */
             } else {
                 exprstate::on_colon_token(tk,
diff --git a/src/reader/expect_type_xs.cpp b/src/reader/expect_type_xs.cpp
index f8efd265..d994257e 100644
--- a/src/reader/expect_type_xs.cpp
+++ b/src/reader/expect_type_xs.cpp
@@ -19,8 +19,8 @@ namespace xo {
         }
 
         void
-        expect_type_xs::start(exprstatestack * p_stack) {
-            p_stack->push_exprstate(expect_type_xs::make());
+        expect_type_xs::start(parserstatemachine * p_psm) {
+            p_psm->push_exprstate(expect_type_xs::make());
         }
 
         expect_type_xs::expect_type_xs()