diff --git a/CMakeLists.txt b/CMakeLists.txt
index 75c24f76d..3123dbea2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -322,10 +322,6 @@ if(GTSAM_ENABLE_CONSISTENCY_CHECKS)
   add_definitions(-DGTSAM_EXTRA_CONSISTENCY_CHECKS)
 endif()
 
-if(GTSAM_ALLOW_DEPRECATED_SINCE_V4)
-	add_definitions(-DGTSAM_ALLOW_DEPRECATED_SINCE_V4)
-endif()
-
 ###############################################################################
 # Add components
 
diff --git a/gtsam/config.h.in b/gtsam/config.h.in
index 20073152e..a408b254c 100644
--- a/gtsam/config.h.in
+++ b/gtsam/config.h.in
@@ -60,4 +60,5 @@
 // Option for not throwing the CheiralityException for points that are behind a camera
 #cmakedefine GTSAM_THROW_CHEIRALITY_EXCEPTION
 
-
+// Make sure dependent projects that want it can see deprecated functions
+#cmakedefine GTSAM_ALLOW_DEPRECATED_SINCE_V4