diff --git a/cmake/CPM.cmake b/cmake/CPM.cmake
index 0ac7637..cb95368 100644
--- a/cmake/CPM.cmake
+++ b/cmake/CPM.cmake
@@ -1,4 +1,5 @@
 set(CPM_DOWNLOAD_VERSION 0.38.1)
+set(CPM_HASH_SUM "9d2072c167bd4b08fb60087553c146515e3f5be061353c321a6d5496eb4bf9ea")
 
 if(CPM_SOURCE_CACHE)
   set(CPM_DOWNLOAD_LOCATION "${CPM_SOURCE_CACHE}/cpm/CPM_${CPM_DOWNLOAD_VERSION}.cmake")
@@ -30,8 +31,8 @@ if(NOT (EXISTS ${CPM_DOWNLOAD_LOCATION}))
   download_cpm()
 else()
   # resume download if it previously failed
-  file(READ ${CPM_DOWNLOAD_LOCATION} check)
-  if("${check}" STREQUAL "")
+  file(SHA256 ${CPM_DOWNLOAD_LOCATION} CPM_CHECK)
+  if(NOT "${CPM_CHECK}" STREQUAL CPM_HASH_SUM)
     download_cpm()
   endif()
 endif()