diff --git a/gtsam/slam/CMakeLists.txt b/gtsam/slam/CMakeLists.txt
index 768ab2307..c25e32bd4 100644
--- a/gtsam/slam/CMakeLists.txt
+++ b/gtsam/slam/CMakeLists.txt
@@ -24,10 +24,6 @@ if (GTSAM_BUILD_TESTS)
     gtsam_add_subdir_tests(slam "${slam_local_libs}" "gtsam-static" "${slam_excluded_files}") 
 endif(GTSAM_BUILD_TESTS)
 
-if(MSVC)
-  add_definitions("/bigobj")
-endif()
-
 # Build timing scripts
 if (GTSAM_BUILD_TIMING)
     gtsam_add_subdir_timing(slam "${slam_local_libs}" "gtsam-static" "${slam_excluded_files}") 
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 9e4c501d4..213d2f5e9 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -25,6 +25,10 @@ set (tests_exclude
     #"${CMAKE_CURRENT_SOURCE_DIR}/testOccupancyGrid.cpp"
 )
 
+if(MSVC)
+  add_definitions("/bigobj") # testSerializationSLAM needs this
+endif()
+
 # Build tests
 if (GTSAM_BUILD_TESTS)
     # Subdirectory target for tests