diff --git a/src/grib_iterator_class.cc b/src/grib_iterator_class.cc
index 7f1bd2b3b..92129285e 100644
--- a/src/grib_iterator_class.cc
+++ b/src/grib_iterator_class.cc
@@ -20,6 +20,34 @@
 /* This file is generated by ./make_class.pl */
 #include "grib_iterator_class.h"
 
+#if GRIB_PTHREADS
+static pthread_once_t once   = PTHREAD_ONCE_INIT;
+static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+
+static void init_mutex()
+{
+    pthread_mutexattr_t attr;
+    pthread_mutexattr_init(&attr);
+    pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
+    pthread_mutex_init(&mutex, &attr);
+    pthread_mutexattr_destroy(&attr);
+}
+#elif GRIB_OMP_THREADS
+static int once = 0;
+static omp_nest_lock_t mutex1;
+
+static void init_mutex()
+{
+    GRIB_OMP_CRITICAL(lock_grib_accessor_class_c)
+    {
+        if (once == 0) {
+            omp_init_nest_lock(&mutex1);
+            once = 1;
+        }
+    }
+}
+#endif
+
 struct table_entry
 {
     const char* type;
@@ -44,7 +72,12 @@ eccodes::grib::geo::Iterator* grib_iterator_factory(grib_handle* h, grib_argumen
             eccodes::grib::geo::Iterator* builder = *(table[i].iterator);
             eccodes::grib::geo::Iterator* it = builder->create();
             it->flags_              = flags;
-            *error                 = it->init(h, args);
+
+            GRIB_MUTEX_INIT_ONCE(&once, &init_mutex);
+            GRIB_MUTEX_LOCK(&mutex);
+            *error = it->init(h, args);
+            GRIB_MUTEX_UNLOCK(&mutex);
+
             if (*error == GRIB_SUCCESS)
                 return it;
             grib_context_log(h->context, GRIB_LOG_ERROR, "Geoiterator factory: Error instantiating iterator %s (%s)",
diff --git a/src/iterator/grib_iterator.cc b/src/iterator/grib_iterator.cc
index e6506c8c4..c9eb26281 100644
--- a/src/iterator/grib_iterator.cc
+++ b/src/iterator/grib_iterator.cc
@@ -18,50 +18,16 @@ namespace eccodes {
 namespace grib {
 namespace geo {
 
-#if GRIB_PTHREADS
-static pthread_once_t once   = PTHREAD_ONCE_INIT;
-static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
-
-static void init_mutex()
-{
-    pthread_mutexattr_t attr;
-    pthread_mutexattr_init(&attr);
-    pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
-    pthread_mutex_init(&mutex, &attr);
-    pthread_mutexattr_destroy(&attr);
-}
-#elif GRIB_OMP_THREADS
-static int once = 0;
-static omp_nest_lock_t mutex;
-
-static void init_mutex()
-{
-    GRIB_OMP_CRITICAL(lock_iterator_c)
-    {
-        if (once == 0) {
-            omp_init_nest_lock(&mutex);
-            once = 1;
-        }
-    }
-}
-#endif
-
 
 int Iterator::init(grib_handle* h, grib_arguments* args)
 {
-    int r = 0;
     h_ = h;
-    //GRIB_MUTEX_INIT_ONCE(&once, &init_mutex);
-    //GRIB_MUTEX_LOCK(&mutex);
-    //r = init_iterator(this, i, h, args);
-    //GRIB_MUTEX_UNLOCK(&mutex);
-    return r;
+    return GRIB_SUCCESS;
 }
 
 /* For this one, ALL destroy are called */
 int Iterator::destroy()
 {
-    //grib_context_free(context_, this);
     delete context_;
     delete this;
     return GRIB_SUCCESS;