diff --git a/llvm/unittests/ExecutionEngine/Orc/CMakeLists.txt b/llvm/unittests/ExecutionEngine/Orc/CMakeLists.txt
index 41fef24556b1..68f6d0c28d7c 100644
--- a/llvm/unittests/ExecutionEngine/Orc/CMakeLists.txt
+++ b/llvm/unittests/ExecutionEngine/Orc/CMakeLists.txt
@@ -20,3 +20,5 @@ add_llvm_unittest(OrcJITTests
   OrcTestCommon.cpp
   RPCUtilsTest.cpp
   )
+
+target_link_libraries(OrcJITTests ${PTHREAD_LIB})