diff --git a/libSimGear.spec b/libSimGear.spec
index ce9fa10..98c6a5b 100644
--- a/libSimGear.spec
+++ b/libSimGear.spec
@@ -1,7 +1,7 @@
 %define		   rel %(echo %version | cut -d. -f1-2)
 Name:          libSimGear
 Version:       2020.3.9
-Release:       1mamba
+Release:       2mamba
 Summary:       Tools and libraries useful for FlightGear
 Group:         System/Libraries
 Vendor:        openmamba
@@ -26,7 +26,7 @@ BuildRequires: libGLUT-devel
 BuildRequires: libopenal-devel >= 0.0
 BuildRequires: libplib-devel >= 1.8.4
 BuildRequires: zlib-devel >= 1.2.2
-BuildRequires: OpenSceneGraph >= 3.4.0
+BuildRequires: libosg-devel >= 3.6.5
 Provides:      SimGear = %{?epoch:%epoch:}%{version}-%{release}
 Obsoletes:     SimGear < 2016.1.1
 
@@ -70,6 +70,9 @@ This package contains static libraries and header files needed for development.
 %doc AUTHORS COPYING
 
 %changelog
+* Tue Jun 22 2021 Silvan Calarco <silvan.calarco@mambasoft.it> 2020.3.9-2mamba
+- rebuilt with OpenSceneGraph 3.6.5
+
 * Sat Jun 19 2021 Silvan Calarco <silvan.calarco@mambasoft.it> 2020.3.9-1mamba
 - update to 2020.3.9