diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6c16afaeb59a..72901c88768b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -287,6 +287,9 @@ option (LLVM_BUILD_DOCS "Build the llvm documentation." OFF)
 option (LLVM_INCLUDE_DOCS "Generate build targets for llvm documentation." ON)
 option (LLVM_ENABLE_DOXYGEN "Use doxygen to generate llvm documentation." OFF)
 
+option (LLVM_BUILD_EXTERNAL_COMPILER_RT
+  "Build compiler-rt as an external project." OFF)
+
 # All options referred to from HandleLLVMOptions have to be specified
 # BEFORE this include, otherwise options will not be correctly set on
 # first cmake run
diff --git a/projects/CMakeLists.txt b/projects/CMakeLists.txt
index 67943c2e9a36..e23a27705620 100644
--- a/projects/CMakeLists.txt
+++ b/projects/CMakeLists.txt
@@ -20,7 +20,9 @@ if(${LLVM_BUILD_RUNTIME})
   if(NOT MSVC)
     add_llvm_external_project(libcxx)
   endif()
-  add_llvm_external_project(compiler-rt)
+  if(NOT LLVM_BUILD_EXTERNAL_COMPILER_RT)
+    add_llvm_external_project(compiler-rt)
+  endif()
 endif()
 
 add_llvm_external_project(dragonegg)