diff --git a/include/maat.h b/include/maat.h
index 70fc1f3..f8cdf38 100644
--- a/include/maat.h
+++ b/include/maat.h
@@ -96,9 +96,9 @@ int maat_options_set_accept_tags(struct maat_options *opts, const char *accept_t
 int maat_options_set_rule_effect_interval_ms(struct maat_options *opts, int interval_ms);
 int maat_options_set_rule_update_checking_interval_ms(struct maat_options *opts, int interval_ms);
 int maat_options_set_gc_timeout_ms(struct maat_options *opts, int interval_ms);
-int maat_options_set_instance_name(struct maat_options *opts, const char *instance_name, size_t name_len);
+int maat_options_set_instance_name(struct maat_options *opts, const char *instance_name);
 int maat_options_set_deferred_load_on(struct maat_options *opts);
-int maat_options_set_foreign_cont_dir(struct maat_options *opts, const char *dir, size_t dir_len);
+int maat_options_set_foreign_cont_dir(struct maat_options *opts, const char *dir);
 
 int maat_options_set_iris(struct maat_options *opts, const char *full_directory, 
                           const char *increment_directory);
diff --git a/src/maat_api.c b/src/maat_api.c
index 2f2b339..9063671 100644
--- a/src/maat_api.c
+++ b/src/maat_api.c
@@ -176,13 +176,14 @@ int maat_options_set_gc_timeout_ms(struct maat_options *opts, int interval_ms)
     return 0;
 }
 
-int maat_options_set_instance_name(struct maat_options *opts, const char *instance_name, size_t name_len)
+int maat_options_set_instance_name(struct maat_options *opts, const char *instance_name)
 {
-    if (NULL == opts || NULL == instance_name || name_len > sizeof(opts->instance_name)) {
+    if (NULL == opts || NULL == instance_name || 
+        strlen(instance_name) >= NAME_MAX) {
         return -1;
     }
 
-    memcpy(opts->instance_name, instance_name, name_len);
+    memcpy(opts->instance_name, instance_name, strlen(instance_name));
     return 0;
 }
 
@@ -196,13 +197,13 @@ int maat_options_set_deferred_load_on(struct maat_options *opts)
     return 0;
 }
 
-int maat_options_set_foreign_cont_dir(struct maat_options *opts, const char *dir, size_t dir_len)
+int maat_options_set_foreign_cont_dir(struct maat_options *opts, const char *dir)
 {
-    if (NULL == opts || NULL == dir || dir_len > sizeof(opts->foreign_cont_dir)) {
+    if (NULL == opts || NULL == dir || strlen(dir) >= NAME_MAX) {
         return -1;
     }
 
-    memcpy(opts->foreign_cont_dir, dir, dir_len);
+    memcpy(opts->foreign_cont_dir, dir, strlen(dir));
     return 0;
 }