diff --git a/clang/lib/CodeGen/CGExprCXX.cpp b/clang/lib/CodeGen/CGExprCXX.cpp
index 54c87a7361b1c4..3cc1443615420b 100644
--- a/clang/lib/CodeGen/CGExprCXX.cpp
+++ b/clang/lib/CodeGen/CGExprCXX.cpp
@@ -1573,7 +1573,7 @@ llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) {
   llvm::Value *allocSize =
     EmitCXXNewAllocSize(*this, E, minElements, numElements,
                         allocSizeWithoutCookie);
-  CharUnits allocAlign = getContext().getPreferredTypeAlignInChars(allocType);
+  CharUnits allocAlign = getContext().getTypeAlignInChars(allocType);
 
   // Emit the allocation call.  If the allocator is a global placement
   // operator, just "inline" it directly.
diff --git a/clang/test/CodeGenCXX/pr54845.cpp b/clang/test/CodeGenCXX/pr54845.cpp
new file mode 100644
index 00000000000000..acf2c3121900b3
--- /dev/null
+++ b/clang/test/CodeGenCXX/pr54845.cpp
@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 -triple i686-linux-gnu -emit-llvm %s -o - | FileCheck %s
+// https://github.com/llvm/llvm-project/issues/54845
+
+void *operator new(unsigned int, void *);
+
+void test(double *d) {
+  // This store used to have an alignment of 8, which was incorrect as
+  // the i386 psABI only guarantees a 4-byte alignment for doubles.
+
+  // CHECK: store double 0.000000e+00, {{.*}}, align 4
+  new (d) double(0);
+}