diff --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
--- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -575,8 +575,10 @@
   }
 
   if (SrcLen == 0) {
-    // strncpy(x, "", y) -> memset(align 1 x, '\0', y)
-    CallInst *NewCI = B.CreateMemSet(Dst, B.getInt8('\0'), Size, Align(1));
+    // strncpy(x, "", y) -> memset(x, '\0', y)
+    Align MemSetAlign =
+        CI->getAttributes().getParamAttributes(0).getAlignment().valueOrOne();
+    CallInst *NewCI = B.CreateMemSet(Dst, B.getInt8('\0'), Size, MemSetAlign);
     AttrBuilder ArgAttrs(CI->getAttributes().getParamAttributes(0));
     NewCI->setAttributes(NewCI->getAttributes().addParamAttributes(
         CI->getContext(), 0, ArgAttrs));
diff --git a/llvm/test/Transforms/InstCombine/strncpy-1.ll b/llvm/test/Transforms/InstCombine/strncpy-1.ll
--- a/llvm/test/Transforms/InstCombine/strncpy-1.ll
+++ b/llvm/test/Transforms/InstCombine/strncpy-1.ll
@@ -144,6 +144,16 @@
   ret i8* %ret
 }
 
+define i8* @test4(i8* %dst, i32 %n) {
+; CHECK-LABEL: @test4(
+; CHECK-NEXT:    call void @llvm.memset.p0i8.i32(i8* noalias noundef nonnull align 16 dereferenceable(5) [[DST:%.*]], i8 0, i32 5, i1 false)
+; CHECK-NEXT:    ret i8* [[DST]]
+;
+  %src = getelementptr [1 x i8], [1 x i8]* @null, i32 0, i32 0
+  %ret = call i8* @strncpy(i8* align(16) noalias nonnull %dst, i8* nonnull %src, i32 5);
+  ret i8* %ret
+}
+
 ; Check cases that shouldn't be simplified.
 
 define void @test_no_simplify1() {