diff --git a/CMakeLists.txt b/CMakeLists.txt
index 18a172a2548..bb70f158800 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -135,6 +135,7 @@ endif()
 set(LLVM_TARGETS_TO_BUILD
    ${LLVM_TARGETS_TO_BUILD}
    ${LLVM_EXPERIMENTAL_TARGETS_TO_BUILD})
+list(REMOVE_DUPLICATES LLVM_TARGETS_TO_BUILD)
 
 set(LLVM_ENUM_TARGETS "")
 foreach(c ${LLVM_TARGETS_TO_BUILD})