diff --git a/sane/gb_json.cpp b/sane/gb_json.cpp
index 967b387..0187200 100644
--- a/sane/gb_json.cpp
+++ b/sane/gb_json.cpp
@@ -178,7 +178,8 @@ namespace gb
         simple_val_.dval = val;
     }
     json::json(const char* key, const char* val) : type_(VAL_TYPE_STRING), key_(key ? key : ""), strval_(val ? val : ""), cur_child_(-1)
-    {}
+    {
+    }
     json::json(json& r)
     {
         copy_from(r);
@@ -1437,6 +1438,7 @@ namespace gb
             name = child->key();
             child->value(raw_v);
             val = sane_config_schm::from_hex_letter(raw_v.c_str(), raw_v.length());
+            child->release();
 
             ret = true;
         }
@@ -1454,6 +1456,7 @@ namespace gb
             name = child->key();
             child->value(raw_v);
             val = sane_config_schm::from_hex_letter(raw_v.c_str(), raw_v.length());
+            child->release();
 
             ret = true;
         }
@@ -1706,6 +1709,7 @@ namespace gb
     {
         clear();
         global_->release();
+        opt_default_value_->release();
     }
 
     bool scanner_cfg::update(const char* file, LPUDF func)
@@ -1776,6 +1780,7 @@ namespace gb
             glb->get_value(scanner_cfg::cur_sel_.c_str(), sel);
             glb->release();
             glb = jsn->first_child();
+            glb->release();
             while ((glb = jsn->next_child()))
             {
                 std::string         val("");
diff --git a/sane/scanner.cpp b/sane/scanner.cpp
index e83802f..b468a8b 100644
--- a/sane/scanner.cpp
+++ b/sane/scanner.cpp
@@ -544,6 +544,7 @@ scanner::~scanner()
 
 	if (cfg_)
 	{
+		cfg_->remove_all_schemes();  // schemes would add_ref on cfg_, so we clear them first. NOTE: do not call save after this !!!
 		cfg_->release();
 		cfg_ = NULL;
 	}