diff --git a/libraries/AC_Fence/AC_Fence.cpp b/libraries/AC_Fence/AC_Fence.cpp
index 1dd416e7ab542c..2f1067c30ffcc8 100644
--- a/libraries/AC_Fence/AC_Fence.cpp
+++ b/libraries/AC_Fence/AC_Fence.cpp
@@ -42,13 +42,16 @@ extern const AP_HAL::HAL& hal;
 
 
 const AP_Param::GroupInfo AC_Fence::var_info[] = {
+
+    // 0 - deprecated enable flag
+
     // @Param: ENABLE
     // @DisplayName: Fence enable/disable
     // @Description: Enabled fence types held as bitmask
     // @Bitmask{Rover}: 1:Circle Centered on Home,2:Inclusion/Exclusion Circles+Polygons
     // @Bitmask{Copter, Plane, Sub}: 0:Max altitude,1:Circle Centered on Home,2:Inclusion/Exclusion Circles+Polygons,3:Min altitude
     // @User: Standard
-    AP_GROUPINFO("ENABLE",      0,  AC_Fence,   _enabled_fences,   0),
+    AP_GROUPINFO("ENABLE",      12,  AC_Fence,   _enabled_fences,   0),
 
     // @Param: TYPE
     // @DisplayName: Fence Type
@@ -144,6 +147,8 @@ const AP_Param::GroupInfo AC_Fence::var_info[] = {
     // @User: Standard
     AP_GROUPINFO_FRAME("OPTIONS", 11, AC_Fence, _options, static_cast<uint16_t>(OPTIONS::DISABLE_MODE_CHANGE), AP_PARAM_FRAME_PLANE),
 
+    // 12 - new enabled flag
+
     AP_GROUPEND
 };
 
@@ -157,6 +162,13 @@ AC_Fence::AC_Fence()
 #endif
     _singleton = this;
     AP_Param::setup_object_defaults(this, var_info);
+
+    // convert old enable parameter
+    uint8_t enable_type = 0;
+    if (AP_Param::get_param_by_index(this, 0, AP_PARAM_INT8, &enable_type) && enable_type) {
+        _enabled_fences = _present_fences;
+        _enabled_fences.save(true);
+    }
 }
 
 /// enable the Fence code generally; a master switch for all fences