diff --git a/llvm/lib/ExecutionEngine/Orc/Layer.cpp b/llvm/lib/ExecutionEngine/Orc/Layer.cpp
--- a/llvm/lib/ExecutionEngine/Orc/Layer.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/Layer.cpp
@@ -125,6 +125,10 @@
   assert(!I->second->isDeclaration() &&
          "Discard should only apply to definitions");
   I->second->setLinkage(GlobalValue::AvailableExternallyLinkage);
+  // According to the IR verifier, "Declaration[s] may not be in a Comdat!"
+  // Remove it, if this is a GlobalObject.
+  if (auto *GO = dyn_cast<GlobalObject>(I->second))
+    GO->setComdat(nullptr);
   SymbolToDefinition.erase(I);
 }
 
diff --git a/llvm/test/ExecutionEngine/Orc/Inputs/weak-comdat-def.ll b/llvm/test/ExecutionEngine/Orc/Inputs/weak-comdat-def.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/ExecutionEngine/Orc/Inputs/weak-comdat-def.ll
@@ -0,0 +1,12 @@
+define i32 @g() {
+entry:
+  ret i32 0
+}
+
+$f = comdat nodeduplicate
+
+define i32 @f() comdat {
+entry:
+  %0 = call i32 @g()
+  ret i32 %0
+}
diff --git a/llvm/test/ExecutionEngine/Orc/weak-comdat.ll b/llvm/test/ExecutionEngine/Orc/weak-comdat.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/ExecutionEngine/Orc/weak-comdat.ll
@@ -0,0 +1,18 @@
+; RUN: lli -extra-module %p/Inputs/weak-comdat-def.ll %s
+; UNSUPPORTED: target={{.*}}-darwin{{.*}}
+
+declare i32 @g()
+
+$f = comdat nodeduplicate
+
+define weak i32 @f() comdat {
+entry:
+  %0 = call i32 @g()
+  ret i32 %0
+}
+
+define i32 @main() {
+entry:
+  %0 = call i32 @f()
+  ret i32 %0
+}