diff --git a/openmp/libomptarget/CMakeLists.txt b/openmp/libomptarget/CMakeLists.txt
--- a/openmp/libomptarget/CMakeLists.txt
+++ b/openmp/libomptarget/CMakeLists.txt
@@ -84,8 +84,15 @@
 
 # Build offloading plugins and device RTLs if they are available.
 add_subdirectory(plugins)
-add_subdirectory(DeviceRTL)
 add_subdirectory(tools)
 
+set(LIBOMPTARGET_LLVM_VERSION "${LLVM_VERSION_MAJOR}.${LLVM_VERSION_MINOR}.${LLVM_VERSION_PATCH}")
+if(CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND CMAKE_CXX_COMPILER_VERSION VERSION_EQUAL LIBOMPTARGET_LLVM_VERSION)
+  add_subdirectory(DeviceRTL)
+else()
+  libomptarget_say("Not building DeviceRTL, CMake compiler '${CMAKE_CXX_COMPILER} ${CMAKE_CXX_COMPILER_VERSION}' is not 'Clang ${LIBOMPTARGET_LLVM_VERSION}'.")
+  libomptarget_say("  Use the 'LLVM_ENABLE_RUNTIMES=openmp' option instead")
+endif()
+
 # Add tests.
 add_subdirectory(test)