diff --git a/include/fluidsynth/settings.h b/include/fluidsynth/settings.h
index a040d09b..5d1f7cb4 100644
--- a/include/fluidsynth/settings.h
+++ b/include/fluidsynth/settings.h
@@ -175,7 +175,7 @@ int fluid_settings_getint_range(fluid_settings_t* settings, const char *name,
  * @param name Setting name
  * @param option A string option for this setting (iterates through the list)
  */
-typedef void (*fluid_settings_foreach_option_t)(void *data, char *name, char *option);
+typedef void (*fluid_settings_foreach_option_t)(void *data, const char *name, const char *option);
 
 FLUIDSYNTH_API
 void fluid_settings_foreach_option(fluid_settings_t* settings,
diff --git a/src/bindings/fluid_cmd.c b/src/bindings/fluid_cmd.c
index 081e4637..dcb907ab 100644
--- a/src/bindings/fluid_cmd.c
+++ b/src/bindings/fluid_cmd.c
@@ -1517,7 +1517,7 @@ struct _fluid_handle_option_data_t {
   fluid_ostream_t out;
 };
 
-void fluid_handle_print_option(void* data, char* name, char* option)
+void fluid_handle_print_option(void* data, const char* name, const char* option)
 {
   struct _fluid_handle_option_data_t* d = (struct _fluid_handle_option_data_t*) data;
 
diff --git a/src/fluidsynth.c b/src/fluidsynth.c
index 47b141d2..f20e9d41 100644
--- a/src/fluidsynth.c
+++ b/src/fluidsynth.c
@@ -141,7 +141,7 @@ typedef struct
 
 /* Function to display each string option value */
 static void
-settings_option_foreach_func (void *data, char *name, char *option)
+settings_option_foreach_func (void *data, const char *name, const char *option)
 {
   OptionBag *bag = data;
 
diff --git a/src/utils/fluid_settings.c b/src/utils/fluid_settings.c
index 25dc7f0a..81927b45 100644
--- a/src/utils/fluid_settings.c
+++ b/src/utils/fluid_settings.c
@@ -1421,7 +1421,7 @@ fluid_settings_foreach_option (fluid_settings_t* settings, const char *name,
   newlist = fluid_list_sort (newlist, fluid_list_str_compare_func);
 
   for (p = newlist; p; p = p->next)
-    (*func)(data, (char *)name, (char *)fluid_list_get (p));
+    (*func)(data, name, (const char *)fluid_list_get (p));
 
   fluid_rec_mutex_unlock (settings->mutex);   /* -- unlock */
 
@@ -1611,7 +1611,7 @@ fluid_settings_foreach (fluid_settings_t* settings, void* data,
   /* Loop over names and call the callback */
   for (p = bag.names; p; p = p->next)
   {
-    if (fluid_settings_get (settings, (char *)(p->data), &node) == FLUID_OK
+    if (fluid_settings_get (settings, (const char *)(p->data), &node) == FLUID_OK
         && node)
         (*func) (data, (char *)(p->data), node->type);
     FLUID_FREE (p->data);       /* -- Free name */