diff --git a/openmp/runtime/src/CMakeLists.txt b/openmp/runtime/src/CMakeLists.txt
index b22d03d168419..6ac047a833fe5 100644
--- a/openmp/runtime/src/CMakeLists.txt
+++ b/openmp/runtime/src/CMakeLists.txt
@@ -10,11 +10,12 @@
 
 include(ExtendPath)
 
-# The generated headers will be placed in clang's resource directory if present.
-if(NOT LLVM_TREE_AVAILABLE)
-  set(LIBOMP_HEADERS_INTDIR ${CMAKE_CURRENT_BINARY_DIR})
-else()
+# The generated headers will be placed in clang's resource if using it to
+# compile openmp in a runtimes-bootstrapping build.
+if(LLVM_TREE_AVAILABLE AND LLVM_RUNTIMES_BUILD)
   set(LIBOMP_HEADERS_INTDIR ${LLVM_BINARY_DIR}/${LIBOMP_HEADERS_INSTALL_PATH})
+else()
+  set(LIBOMP_HEADERS_INTDIR ${CMAKE_CURRENT_BINARY_DIR})
 endif()
 
 # Configure omp.h, kmp_config.h and omp-tools.h if necessary