Index: generic/nsf.c
===================================================================
diff -u -r75ac8b23b5aca02319f4dda1678082c0334bedc4 -r6a52879a99a2fd5bc2e987d5b1149f69d35f02d9
--- generic/nsf.c	(.../nsf.c)	(revision 75ac8b23b5aca02319f4dda1678082c0334bedc4)
+++ generic/nsf.c	(.../nsf.c)	(revision 6a52879a99a2fd5bc2e987d5b1149f69d35f02d9)
@@ -31706,9 +31706,12 @@
   NsfStringIncrFree(&rst->iss);
 
   /*
-   * Free all data in the pointer converter.
+   * Free all data in the hash tables managing pointer converters,
+   * enumerations, and method definitions.
    */
   Nsf_PointerExit(interp);
+  Nsf_EnumerationTypeRelease(interp);
+  Nsf_CmdDefinitionRelease(interp);
 
 #if defined(NSF_PROFILE)
   NsfProfileFree(interp);
@@ -31753,9 +31756,6 @@
     }
   }
 #endif
-
-  Nsf_EnumerationTypeRelease(interp);
-  Nsf_CmdDefinitionRelease(interp);
   
   Tcl_Interp_flags(interp) = flags;
   Tcl_Release(interp);
Index: generic/nsfCmdDefinitions.c
===================================================================
diff -u -ra2021fcacd45bfbbe0d2dc11061e2a374c49726f -r6a52879a99a2fd5bc2e987d5b1149f69d35f02d9
--- generic/nsfCmdDefinitions.c	(.../nsfCmdDefinitions.c)	(revision a2021fcacd45bfbbe0d2dc11061e2a374c49726f)
+++ generic/nsfCmdDefinitions.c	(.../nsfCmdDefinitions.c)	(revision 6a52879a99a2fd5bc2e987d5b1149f69d35f02d9)
@@ -1,8 +1,9 @@
 /*
  * nsfCmdDefinitions.c --
  *
- *      Provide an API for registering method definitions
- *      and obtaining these meta-data for introspection.
+ *      Provide an API for registering method definitions and obtaining these
+ *      meta-data for introspection. Method definitions are shared by all
+ *      threads/interps. Access is governed by a mutex lock.
  *
  * Copyright (C) 2014-2016 Gustaf Neumann
  * Copyright (C) 2016 Stefan Sobernig
Index: generic/nsfEnumerationType.c
===================================================================
diff -u -ra2021fcacd45bfbbe0d2dc11061e2a374c49726f -r6a52879a99a2fd5bc2e987d5b1149f69d35f02d9
--- generic/nsfEnumerationType.c	(.../nsfEnumerationType.c)	(revision a2021fcacd45bfbbe0d2dc11061e2a374c49726f)
+++ generic/nsfEnumerationType.c	(.../nsfEnumerationType.c)	(revision 6a52879a99a2fd5bc2e987d5b1149f69d35f02d9)
@@ -1,8 +1,9 @@
 /*
  * nsfEnumerationType.c --
  *
- *      Provide an API for registering enumeration types
- *      and obtaining their domains.
+ *      Provide an API for registering enumeration types and obtaining their
+ *      domains. Enumeration types are shared by all threads/interps. Access
+ *      is governed by a mutex lock.
  *
  * Copyright (C) 2014 Gustaf Neumann
  * Copyright (C) 2016 Stefan Sobernig