diff --git a/src/TclString.pm b/src/TclString.pm
index 9846183..26595f0 100644
--- a/src/TclString.pm
+++ b/src/TclString.pm
@@ -1,5 +1,12 @@
 # This class is currently created via PIR in src/class/tclstring.pir
 
+INIT {
+    pir::getinterp__p().hll_map(
+        pir::get_class__ps('String'),
+        pir::get_class__ps('TclString')
+    )
+}
+
 module TclString {
 
     method getInteger() { ## :is vtable
diff --git a/src/class/tclstring.pir b/src/class/tclstring.pir
index a31e7a3..ec68402 100644
--- a/src/class/tclstring.pir
+++ b/src/class/tclstring.pir
@@ -15,18 +15,6 @@ A Tcl-style string
   tcl = subclass core, 'TclString'
 .end
 
-
-.sub 'mapping' :anon :init
-  .local pmc tcl
-  tcl  = get_class 'TclString'
-  .local pmc interp
-  interp = getinterp
-
-  .local pmc core
-  core = get_class 'String'
-  interp.'hll_map'(core,tcl)
-.end
-
 .namespace [ 'TclString' ]
 .sub get_bool :vtable
     .tailcall self.'getBoolean'()