diff --git a/CMakeLists.txt b/CMakeLists.txt
index 686ada1e4..5599c1b59 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -28,7 +28,7 @@ set(CRYPTOPP_INCLUDE_DIR "../cryptopp562" CACHE FILEPATH "" FORCE)
 set(CRYPTOPP_LIBRARIES "../cryptopp562" CACHE FILEPATH "" FORCE)
 
 # Look for availabe Crypto++ version and if it is >= 5.6.2
-if(EXISTS CRYPTOPP_INCLUDE_DIR AND EXISTS CRYPTOPP_LIBRARIES)
+if(EXISTS ${CRYPTOPP_INCLUDE_DIR} AND EXISTS ${CRYPTOPP_LIBRARIES})
 	   set(CRYPTOPP_FOUND TRUE)
 	   message(STATUS "Found Crypto++: ${CRYPTOPP_INCLUDE_DIR}, ${CRYPTOPP_LIBRARIES}")
 else()