diff --git a/cmake/px4_add_board.cmake b/cmake/px4_add_board.cmake
index f8d3c4dd34..6b7fd16188 100644
--- a/cmake/px4_add_board.cmake
+++ b/cmake/px4_add_board.cmake
@@ -277,6 +277,7 @@ function(px4_add_board)
 
 	if(CRYPTO)
 		set(PX4_CRYPTO ${CRYPTO} CACHE STRING "PX4 crypto implementation" FORCE)
+		add_definitions(-DPX4_CRYPTO)
 	endif()
 
 	if(KEYSTORE)