diff --git a/CMakeLists.txt b/CMakeLists.txt
index b07e486c..aba846c2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -106,7 +106,7 @@ if (RAIBLOCKS_GUI)
 endif (RAIBLOCKS_GUI)
 
 if (RAIBLOCKS_SECURE_RPC)
-	find_package (OpenSSL REQUIRED)
+	find_package (OpenSSL 1.0 EXACT REQUIRED)
 	include_directories(${OPENSSL_INCLUDE_DIR})
 	add_definitions (-DRAIBLOCKS_SECURE_RPC)
 	message("OpenSSL include dir: ${OPENSSL_INCLUDE_DIR}")