diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5294fae6..723b2b7a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -45,6 +45,19 @@ SET(TAGLIB_LIB_PATCH_VERSION "0")
 SET(TAGLIB_LIB_VERSION_STRING "${TAGLIB_LIB_MAJOR_VERSION}.${TAGLIB_LIB_MINOR_VERSION}.${TAGLIB_LIB_PATCH_VERSION}")
 
 
+# 1. If the library source code has changed at all since the last update, then increment revision.
+# 2. If any interfaces have been added, removed, or changed since the last update, increment current, and set revision to 0.
+# 3. If any interfaces have been added since the last public release, then increment age.
+# 4. If any interfaces have been removed since the last public release, then set age to 0. 
+SET(TAGLIB_SOVERSION_CURRENT  11)
+SET(TAGLIB_SOVERSION_REVISION 0)
+SET(TAGLIB_SOVERSION_AGE      10)
+
+MATH(EXPR TAGLIB_SOVERSION_MAJOR "${TAGLIB_SOVERSION_CURRENT} - ${TAGLIB_SOVERSION_AGE}")
+MATH(EXPR TAGLIB_SOVERSION_MINOR "${TAGLIB_SOVERSION_AGE}")
+MATH(EXPR TAGLIB_SOVERSION_PATCH "${TAGLIB_SOVERSION_REVISION}")
+
+
 include(ConfigureChecks.cmake)
 
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/taglib-config.cmake ${CMAKE_CURRENT_BINARY_DIR}/taglib-config )
diff --git a/taglib/CMakeLists.txt b/taglib/CMakeLists.txt
index f050a5c4..23f4796b 100644
--- a/taglib/CMakeLists.txt
+++ b/taglib/CMakeLists.txt
@@ -204,8 +204,8 @@ if(ZLIB_FOUND)
 endif(ZLIB_FOUND)
 
 SET_TARGET_PROPERTIES(tag PROPERTIES
-        VERSION ${TAGLIB_LIB_MAJOR_VERSION}.${TAGLIB_LIB_MINOR_VERSION}.${TAGLIB_LIB_PATCH_VERSION}
-        SOVERSION ${TAGLIB_LIB_MAJOR_VERSION}
+        VERSION ${TAGLIB_SOVERSION_MAJOR}.${TAGLIB_SOVERSION_MINOR}.${TAGLIB_SOVERSION_PATCH}
+        SOVERSION ${TAGLIB_SOVERSION_MAJOR}
         INSTALL_NAME_DIR ${LIB_INSTALL_DIR}
         DEFINE_SYMBOL MAKE_TAGLIB_LIB
         LINK_INTERFACE_LIBRARIES ""