diff --git a/cmake/DownloadLibCurl.cmake b/cmake/DownloadLibCurl.cmake
index a94c6a6fe..022a7377c 100644
--- a/cmake/DownloadLibCurl.cmake
+++ b/cmake/DownloadLibCurl.cmake
@@ -12,6 +12,10 @@ file(MAKE_DIRECTORY ${LIBCURL_PREFIX}/include)
 
 include(ExternalProject)
 include(ProcessorCount)
+ProcessorCount(PROCESSOR_COUNT)
+if(PROCESSOR_COUNT EQUAL 0)
+    set(PROCESSOR_COUNT 1)
+endif()
 
 set(libcurl_cc ${CMAKE_C_COMPILER})
 if(CCACHE_PROGRAM)
diff --git a/cmake/DownloadLibSodium.cmake b/cmake/DownloadLibSodium.cmake
index 69d39fb33..d97c6a934 100644
--- a/cmake/DownloadLibSodium.cmake
+++ b/cmake/DownloadLibSodium.cmake
@@ -12,6 +12,10 @@ file(MAKE_DIRECTORY ${LIBSODIUM_PREFIX}/include)
 
 include(ExternalProject)
 include(ProcessorCount)
+ProcessorCount(PROCESSOR_COUNT)
+if(PROCESSOR_COUNT EQUAL 0)
+    set(PROCESSOR_COUNT 1)
+endif()
 
 set(sodium_cc ${CMAKE_C_COMPILER})
 if(CCACHE_PROGRAM)