diff --git a/src/aotcompile.cpp b/src/aotcompile.cpp
index 467ae359e4eb5..f0011e4488b1d 100644
--- a/src/aotcompile.cpp
+++ b/src/aotcompile.cpp
@@ -1634,7 +1634,11 @@ void jl_dump_native_impl(void *native_code,
             jl_ExecutionEngine->getTargetOptions(),
             RelocModel,
             CMModel,
+#if JL_LLVM_VERSION >= 180000
+            CodeGenOptLevel::Aggressive // -O3 TODO: respect command -O0 flag?
+#else
             CodeGenOpt::Aggressive // -O3 TODO: respect command -O0 flag?
+#endif
             ));
     fixupTM(*SourceTM);
     auto DL = jl_create_datalayout(*SourceTM);
diff --git a/src/jitlayers.cpp b/src/jitlayers.cpp
index d1da55d98f8be..f33e9427ad74d 100644
--- a/src/jitlayers.cpp
+++ b/src/jitlayers.cpp
@@ -568,6 +568,19 @@ jl_value_t *jl_dump_method_asm_impl(jl_method_instance_t *mi, size_t world,
     return jl_an_empty_string;
 }
 
+#if JL_LLVM_VERSION >= 180000
+CodeGenOptLevel CodeGenOptLevelFor(int optlevel)
+{
+#ifdef DISABLE_OPT
+    return CodeGenOptLevel::None;
+#else
+    return optlevel == 0 ? CodeGenOptLevel::None :
+        optlevel == 1 ? CodeGenOptLevel::Less :
+        optlevel == 2 ? CodeGenOptLevel::Default :
+        CodeGenOptLevel::Aggressive;
+#endif
+}
+#else
 CodeGenOpt::Level CodeGenOptLevelFor(int optlevel)
 {
 #ifdef DISABLE_OPT
@@ -579,6 +592,7 @@ CodeGenOpt::Level CodeGenOptLevelFor(int optlevel)
         CodeGenOpt::Aggressive;
 #endif
 }
+#endif
 
 static auto countBasicBlocks(const Function &F) JL_NOTSAFEPOINT
 {
diff --git a/src/jitlayers.h b/src/jitlayers.h
index 1eea3692aec71..5e1759e482016 100644
--- a/src/jitlayers.h
+++ b/src/jitlayers.h
@@ -26,6 +26,7 @@
 #include "julia_internal.h"
 #include "platform.h"
 #include "llvm-codegen-shared.h"
+#include "llvm-version.h"
 #include <stack>
 #include <queue>
 
@@ -644,4 +645,8 @@ void optimizeDLSyms(Module &M);
 // NewPM
 #include "passes.h"
 
+#if JL_LLVM_VERSION >= 180000
+CodeGenOptLevel CodeGenOptLevelFor(int optlevel) JL_NOTSAFEPOINT;
+#else
 CodeGenOpt::Level CodeGenOptLevelFor(int optlevel) JL_NOTSAFEPOINT;
+#endif