diff --git a/llvm/tools/llvm-reduce/deltas/ReduceGlobalValues.cpp b/llvm/tools/llvm-reduce/deltas/ReduceGlobalValues.cpp
--- a/llvm/tools/llvm-reduce/deltas/ReduceGlobalValues.cpp
+++ b/llvm/tools/llvm-reduce/deltas/ReduceGlobalValues.cpp
@@ -24,7 +24,7 @@
 
   // remove dso_local from global values
   for (auto &GV : Program->global_values())
-    if (GV.isDSOLocal() && !O.shouldKeep()) {
+    if (GV.isDSOLocal() && !GV.isImplicitDSOLocal() && !O.shouldKeep()) {
       GV.setDSOLocal(false);
     }
 }