diff --git a/llvm/lib/Transforms/Scalar/Reassociate.cpp b/llvm/lib/Transforms/Scalar/Reassociate.cpp
index e742d2ed12af1..bc50f23d8eb27 100644
--- a/llvm/lib/Transforms/Scalar/Reassociate.cpp
+++ b/llvm/lib/Transforms/Scalar/Reassociate.cpp
@@ -874,6 +874,8 @@ static Value *NegateValue(Value *V, Instruction *BI,
   // negation.
   Instruction *NewNeg =
       CreateNeg(V, V->getName() + ".neg", BI->getIterator(), BI);
+  // NewNeg is generated to potentially replace BI, so use its DebugLoc.
+  NewNeg->setDebugLoc(BI->getDebugLoc());
   ToRedo.insert(NewNeg);
   return NewNeg;
 }
diff --git a/llvm/test/Transforms/Reassociate/preserve-debugloc.ll b/llvm/test/Transforms/Reassociate/preserve-debugloc.ll
new file mode 100644
index 0000000000000..ff1f8ac73410a
--- /dev/null
+++ b/llvm/test/Transforms/Reassociate/preserve-debugloc.ll
@@ -0,0 +1,38 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+;; Tests that we preserve DebugLocs through reassociation of sub instructions.
+; RUN: opt < %s -passes=reassociate -S | FileCheck %s
+
+define void @foo(i64 %0) {
+; CHECK-LABEL: define void @foo(
+; CHECK-SAME: i64 [[TMP0:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[DOTNEG:%.*]] = sub i64 0, [[TMP0]], !dbg [[DBG3:![0-9]+]]
+; CHECK-NEXT:    [[ADD_I_I:%.*]] = add i64 [[DOTNEG]], 1
+; CHECK-NEXT:    store i64 [[ADD_I_I]], ptr null, align 8
+; CHECK-NEXT:    ret void
+;
+entry:
+  %sub5.i.i = sub i64 1, %0, !dbg !4
+  %add.i.i = add i64 %sub5.i.i, 0
+  store i64 %add.i.i, ptr null, align 8
+  ret void
+}
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 20.0.0git", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug)
+!1 = !DIFile(filename: "test.cpp", directory: "/tmp")
+!2 = !{}
+!3 = !{i32 2, !"Debug Info Version", i32 3}
+!4 = !DILocation(line: 212, column: 25, scope: !5)
+!5 = distinct !DISubprogram(name: "foo", scope: !0, file: !1, line: 161, type: !6, scopeLine: 162, unit: !0, retainedNodes: !2)
+!6 = distinct !DISubroutineType(types: !2)
+;.
+; CHECK: [[META0:![0-9]+]] = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: [[META1:![0-9]+]], producer: "{{.*}}clang version {{.*}}", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug)
+; CHECK: [[META1]] = !DIFile(filename: "test.cpp", directory: {{.*}})
+; CHECK: [[DBG3]] = !DILocation(line: 212, column: 25, scope: [[META4:![0-9]+]])
+; CHECK: [[META4]] = distinct !DISubprogram(name: "foo", scope: [[META0]], file: [[META1]], line: 161, type: [[META5:![0-9]+]], scopeLine: 162, spFlags: DISPFlagDefinition, unit: [[META0]], retainedNodes: [[META6:![0-9]+]])
+; CHECK: [[META5]] = distinct !DISubroutineType(types: [[META6]])
+; CHECK: [[META6]] = !{}
+;.