diff --git a/CHANGES b/CHANGES
index d2019aef..29a92491 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,6 +1,8 @@
 v3.0.x - YYYY-MMM-DD (To be released)
 -------------------------------------
 
+ - Fix SecUploadDir configuration merge
+   [Issue #1720 - @zimmerle, @gjvanetten]
  - Include all prerequisites for "make check" into dist archive
    [Issue #1716 - @defanator]
  - Fix: Reverse logic of checking output in @inspectFile
diff --git a/headers/modsecurity/rules_properties.h b/headers/modsecurity/rules_properties.h
index a9b1b8fe..5f095d86 100644
--- a/headers/modsecurity/rules_properties.h
+++ b/headers/modsecurity/rules_properties.h
@@ -328,26 +328,31 @@ class RulesProperties {
 
         if (from->m_uploadDirectory.m_set == true) {
             to->m_uploadDirectory.m_value = from->m_uploadDirectory.m_value;
+            to->m_uploadDirectory.m_set = true;
         }
 
         if (from->m_uploadTmpDirectory.m_set == true) {
             to->m_uploadTmpDirectory.m_value = \
                 from->m_uploadTmpDirectory.m_value;
+            to->m_uploadTmpDirectory.m_set = true;
         }
 
         if (from->m_secArgumentSeparator.m_set == true) {
             to->m_secArgumentSeparator.m_value = \
                 from->m_secArgumentSeparator.m_value;
+            to->m_secArgumentSeparator.m_set = true;
         }
 
         if (from->m_secWebAppId.m_set == true) {
             to->m_secWebAppId.m_value = \
                 from->m_secWebAppId.m_value;
+            to->m_secWebAppId.m_set = true;
         }
 
         if (from->m_unicodeMapTable.m_set == true) {
             to->m_unicodeMapTable.m_unicode_map_table = \
                 from->m_unicodeMapTable.m_unicode_map_table;
+            to->m_unicodeMapTable.m_set = true;
         }
 
         if (from->m_httpblKey.m_set == true) {