diff --git a/CMakeLists.txt b/CMakeLists.txt
index 431b3c737..a18986278 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -121,7 +121,6 @@ set(LT_VERSION "${LT_MAJOR}.${LT_AGE}.${LT_REVISION}")
 # which are normally 0-based.
 math(EXPR DYLIB_CURRENT_VERSION_MAJOR "${LT_MAJOR} + ${LT_AGE} + 1")
 math(EXPR DYLIB_CURRENT_VERSION_MINOR "${LT_REVISION}")
-math(EXPR DYLIB_COMPAT_VERSION_MAJOR "${LT_MAJOR} + 1")
 set(DYLIB_CURRENT_VERSION "${DYLIB_CURRENT_VERSION_MAJOR}.${DYLIB_CURRENT_VERSION_MINOR}.0")
 set(DYLIB_COMPATIBILITY_VERSION "${DYLIB_CURRENT_VERSION_MAJOR}.0.0")