diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -12051,7 +12051,16 @@
     checkObjCDictionaryLiteral(S, QualType(Target, 0), DictionaryLiteral);
 
   // Strip vector types.
-  if (isa<VectorType>(Source)) {
+  if (const auto *SourceVT = dyn_cast<VectorType>(Source)) {
+    if (Target->isVLSTBuiltinType()) {
+      auto SourceVectorKind = SourceVT->getVectorKind();
+      if (SourceVectorKind == VectorType::SveFixedLengthDataVector ||
+          SourceVectorKind == VectorType::SveFixedLengthPredicateVector ||
+          (SourceVectorKind == VectorType::GenericVector &&
+           S.Context.getTypeSize(Source) == S.getLangOpts().ArmSveVectorBits))
+        return;
+    }
+
     if (!isa<VectorType>(Target)) {
       if (S.SourceMgr.isInSystemMacro(CC))
         return;
diff --git a/clang/test/SemaCXX/attr-arm-sve-vector-bits.cpp b/clang/test/SemaCXX/attr-arm-sve-vector-bits.cpp
--- a/clang/test/SemaCXX/attr-arm-sve-vector-bits.cpp
+++ b/clang/test/SemaCXX/attr-arm-sve-vector-bits.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -target-feature +bf16 -ffreestanding -fsyntax-only -verify -std=c++11 -msve-vector-bits=512 -fallow-half-arguments-and-returns %s
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -target-feature +bf16 -ffreestanding -fsyntax-only -verify -std=c++11 -msve-vector-bits=512 -fallow-half-arguments-and-returns -Wconversion %s
 // expected-no-diagnostics
 
 #include <stdint.h>