diff --git a/crypto/CMakeLists.txt b/crypto/CMakeLists.txt
index c21fce5..1e7baae 100644
--- a/crypto/CMakeLists.txt
+++ b/crypto/CMakeLists.txt
@@ -933,7 +933,7 @@ if(NOT "${OPENSSLDIR}" STREQUAL "")
 	add_definitions(-DOPENSSLDIR=\"${OPENSSLDIR}\")
 else()
 	if(WIN32)
-		add_definitions(-DOPENSSLDIR=C:/libressl/ssl)
+		add_definitions(-DOPENSSLDIR=\"C:/libressl/ssl\")
 	else()
 		add_definitions(-DOPENSSLDIR=\"${CMAKE_INSTALL_PREFIX}/etc/ssl\")
 	endif()