diff --git a/openmp/CMakeLists.txt b/openmp/CMakeLists.txt
index c206386fa6b61..ab34851d8961c 100644
--- a/openmp/CMakeLists.txt
+++ b/openmp/CMakeLists.txt
@@ -115,7 +115,7 @@ option(OPENMP_ENABLE_LIBOMPTARGET "Enable building libomptarget for offloading."
 option(OPENMP_ENABLE_LIBOMP_PROFILING "Enable time profiling for libomp." OFF)
 
 # Header install location
-if(${OPENMP_STANDALONE_BUILD})
+if(NOT LLVM_TREE_AVAILABLE)
   set(LIBOMP_HEADERS_INSTALL_PATH "${CMAKE_INSTALL_INCLUDEDIR}")
 else()
   include(GetClangResourceDir)
diff --git a/openmp/runtime/src/CMakeLists.txt b/openmp/runtime/src/CMakeLists.txt
index 698e185d9c4dd..569061c6494b8 100644
--- a/openmp/runtime/src/CMakeLists.txt
+++ b/openmp/runtime/src/CMakeLists.txt
@@ -11,7 +11,7 @@
 include(ExtendPath)
 
 # The generated headers will be placed in clang's resource directory if present.
-if(OPENMP_STANDALONE_BUILD OR NOT LLVM_RUNTIMES_BUILD)
+if(NOT LLVM_TREE_AVAILABLE)
   set(LIBOMP_HEADERS_INTDIR ${CMAKE_CURRENT_BINARY_DIR})
 else()
   set(LIBOMP_HEADERS_INTDIR ${LLVM_BINARY_DIR}/${LIBOMP_HEADERS_INSTALL_PATH})
diff --git a/runtimes/CMakeLists.txt b/runtimes/CMakeLists.txt
index e4dd4ebfc678d..d0d2a538e1e85 100644
--- a/runtimes/CMakeLists.txt
+++ b/runtimes/CMakeLists.txt
@@ -92,6 +92,14 @@ include(LLVMCheckCompilerLinkerFlag)
 include(CheckCCompilerFlag)
 include(CheckCXXCompilerFlag)
 
+
+# Determine whether we are in the runtimes/runtimes-bins directory of a
+# bootstrap build.
+set(LLVM_TREE_AVAILABLE OFF)
+if (LLVM_LIBRARY_OUTPUT_INTDIR AND LLVM_RUNTIME_OUTPUT_INTDIR AND PACKAGE_VERSION)
+  set(LLVM_TREE_AVAILABLE ON)
+endif()
+
 # CMake omits default compiler include paths, but in runtimes build, we use
 # -nostdinc and -nostdinc++ and control include paths manually so this behavior
 # is undesirable. Filtering CMAKE_{LANG}_IMPLICIT_INCLUDE_DIRECTORIES to remove