diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1f2c67e..2833d93 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -19,12 +19,16 @@ endif()
 
 message(STATUS MONERO_DIR ": ${MONERO_DIR}")
 
-set(MONERO_SOURCE_DIR ${MONERO_DIR}
-        CACHE PATH "Path to the root directory for Monero")
+if (NOT MONERO_SOURCE_DIR)
+    set(MONERO_SOURCE_DIR ${MONERO_DIR}
+          CACHE PATH "Path to the root directory for Monero")
+endif()
 
-# set location of monero build tree
-set(MONERO_BUILD_DIR ${MONERO_SOURCE_DIR}/build/release/
-        CACHE PATH "Path to the build directory for Monero")
+if (NOT MONERO_BUILD_DIR)
+    # set location of monero build tree
+    set(MONERO_BUILD_DIR ${MONERO_SOURCE_DIR}/build/release/
+          CACHE PATH "Path to the build directory for Monero")
+endif()
 
 set(MY_CMAKE_DIR "${CMAKE_CURRENT_LIST_DIR}/cmake"
         CACHE PATH "The path to the cmake directory of the current project")