diff --git a/hgdriver/hgdev/hg_scanner.cpp b/hgdriver/hgdev/hg_scanner.cpp
index b35f914..f79ba11 100644
--- a/hgdriver/hgdev/hg_scanner.cpp
+++ b/hgdriver/hgdev/hg_scanner.cpp
@@ -1525,6 +1525,10 @@ int hg_scanner::setting_restore(void* data, long* len)
 				restore(v.first.c_str());
 		}
 	}
+	memset(custom_gamma_val_, 0, sizeof(SANE_Gamma));
+	for (int i = 0; i < ARRAY_SIZE(custom_gamma_val_->table); ++i)
+		custom_gamma_val_->table[i] = i & 0x0ff;
+
 	notify_setting_result_ = true;
 
 	return SCANNER_ERR_CONFIGURATION_CHANGED;