diff --git a/src/lib/error.c b/src/lib/error.c
index dc9acfa56..1d3fb50c3 100644
--- a/src/lib/error.c
+++ b/src/lib/error.c
@@ -46,12 +46,12 @@ lumiera_error_tls_init (void)
 }
 
 
-const char*
-lumiera_error_set (const char * nerr)
+lumiera_err
+lumiera_error_set (lumiera_err nerr)
 {
   pthread_once (&lumiera_error_initialized, lumiera_error_tls_init);
 
-  const char* err = pthread_getspecific (lumiera_error_tls);
+  lumiera_err err = pthread_getspecific (lumiera_error_tls);
   if (!err)
     pthread_setspecific (lumiera_error_tls, nerr);
 
@@ -59,12 +59,12 @@ lumiera_error_set (const char * nerr)
 }
 
 
-const char*
+lumiera_err
 lumiera_error ()
 {
   pthread_once (&lumiera_error_initialized, lumiera_error_tls_init);
 
-  const char* err = pthread_getspecific (lumiera_error_tls);
+  lumiera_err err = pthread_getspecific (lumiera_error_tls);
   if (err)
     pthread_setspecific (lumiera_error_tls, NULL);
   return err;
diff --git a/src/lib/error.h b/src/lib/error.h
index e00e69c6b..5c4a8c145 100644
--- a/src/lib/error.h
+++ b/src/lib/error.h
@@ -35,6 +35,7 @@ extern "C" {
  * C Error handling in Lumiera, header.
  */
 
+typedef const char* lumiera_err;
 
 /**
  * Abort unconditionally with a 'Fatal Error!' message.
@@ -49,7 +50,7 @@ extern "C" {
  * @param err name of the error without the 'LUMIERA_ERROR_' prefix (example: NO_MEMORY)
  */
 #define LUMIERA_ERROR_DECLARE(err) \
-extern const char* LUMIERA_ERROR_##err
+extern lumiera_err LUMIERA_ERROR_##err
 
 /**
  * Definition and initialization of an error constant.
@@ -58,7 +59,7 @@ extern const char* LUMIERA_ERROR_##err
  * @param msg message describing the error in plain english (example: "memory allocation failed")
  */
 #define LUMIERA_ERROR_DEFINE(err, msg) \
-const char* LUMIERA_ERROR_##err = "LUMIERA_ERROR_" #err ":" msg
+lumiera_err LUMIERA_ERROR_##err = "LUMIERA_ERROR_" #err ":" msg
 
 /**
  * Helper macro to raise an error for the current thread.
@@ -77,8 +78,8 @@ lumiera_error_set(LUMIERA_ERROR_##err))
  * @return old state, that is NULL for success, when the state was cleared and a pointer to a pending 
  * error when the error state was already set
  */
-const char*
-lumiera_error_set (const char * err);
+lumiera_err
+lumiera_error_set (lumiera_err err);
 
 /**
  * Get and clear current error state.
@@ -86,7 +87,7 @@ lumiera_error_set (const char * err);
  * variable.
  * @return pointer to any pending error of this thread, NULL if no error is pending
  */
-const char*
+lumiera_err
 lumiera_error ();
 
 /*