diff --git a/clang-tools-extra/clangd/unittests/SerializationTests.cpp b/clang-tools-extra/clangd/unittests/SerializationTests.cpp
--- a/clang-tools-extra/clangd/unittests/SerializationTests.cpp
+++ b/clang-tools-extra/clangd/unittests/SerializationTests.cpp
@@ -310,7 +310,7 @@
 
 // rlimit is part of POSIX.
 // Sanitizers use a lot of address space, so we can't apply strict limits.
-#if LLVM_ON_UNIX && !LLVM_ADDRESS_SANITIZER_BUILD &&                           \
+#if LLVM_ON_UNIX && defined(RLIMIT_AS) && !LLVM_ADDRESS_SANITIZER_BUILD &&     \
     !LLVM_MEMORY_SANITIZER_BUILD
 class ScopedMemoryLimit {
   struct rlimit OriginalLimit;
diff --git a/llvm/tools/llvm-rtdyld/llvm-rtdyld.cpp b/llvm/tools/llvm-rtdyld/llvm-rtdyld.cpp
--- a/llvm/tools/llvm-rtdyld/llvm-rtdyld.cpp
+++ b/llvm/tools/llvm-rtdyld/llvm-rtdyld.cpp
@@ -286,7 +286,7 @@
   uintptr_t SlabSize = 0;
   uintptr_t CurrentSlabOffset = 0;
   SectionIDMap *SecIDMap = nullptr;
-#if defined(__x86_64__) && defined(__ELF__)
+#if defined(__x86_64__) && defined(__ELF__) && !defined(__OpenBSD__)
   unsigned UsedTLSStorage = 0;
 #endif
 };
@@ -350,7 +350,7 @@
 
 // In case the execution needs TLS storage, we define a very small TLS memory
 // area here that will be used in allocateTLSSection().
-#if defined(__x86_64__) && defined(__ELF__)
+#if defined(__x86_64__) && defined(__ELF__) && !defined(__OpenBSD__)
 extern "C" {
 alignas(16) __attribute__((visibility("hidden"), tls_model("initial-exec"),
                            used)) thread_local char LLVMRTDyldTLSSpace[16];
@@ -361,7 +361,7 @@
 TrivialMemoryManager::allocateTLSSection(uintptr_t Size, unsigned Alignment,
                                          unsigned SectionID,
                                          StringRef SectionName) {
-#if defined(__x86_64__) && defined(__ELF__)
+#if defined(__x86_64__) && defined(__ELF__) && !defined(__OpenBSD__)
   if (Size + UsedTLSStorage > sizeof(LLVMRTDyldTLSSpace)) {
     return {};
   }