diff --git a/gtsam/3rdparty/CMakeLists.txt b/gtsam/3rdparty/CMakeLists.txt
index 6ca7514ac..9a99bdba8 100644
--- a/gtsam/3rdparty/CMakeLists.txt
+++ b/gtsam/3rdparty/CMakeLists.txt
@@ -41,6 +41,10 @@ add_subdirectory(ceres)
 # add_subdirectory (tools)
 
 # Find GeographicLib using the find script distributed with it
+unset(GEOGRAPHICLIB_FOUND CACHE)
+unset(GeographicLib_INCLUDE_DIRS CACHE)
+unset(GeographicLib_LIBRARIES CACHE)
+unset(GeographicLib_LIBRARY_DIRS CACHE)
 include(GeographicLib/cmake/FindGeographicLib.cmake)
 
 # Set up the option to install GeographicLib