diff --git a/clang/lib/Sema/SemaSYCL.cpp b/clang/lib/Sema/SemaSYCL.cpp
index 99d9cbe1f4f60..1f33eb1598080 100644
--- a/clang/lib/Sema/SemaSYCL.cpp
+++ b/clang/lib/Sema/SemaSYCL.cpp
@@ -6990,7 +6990,10 @@ ExprResult SemaSYCL::ActOnUniqueStableNameExpr(SourceLocation OpLoc,
 }
 
 void SemaSYCL::performSYCLDelayedAttributesAnalaysis(const FunctionDecl *FD) {
-  if (SYCLKernelFunctions.contains(FD))
+  // To avoid confusing, we skip issuing warnings for functors that are defined
+  // but not used.
+  if (SYCLKernelFunctions.contains(FD) ||
+      (FD->getOverloadedOperator() == OverloadedOperatorKind::OO_Call))
     return;
 
   for (const auto *KernelAttr : std::vector<AttributeCommonInfo *>{
diff --git a/clang/test/SemaSYCL/check-work-group-size-hint-device.cpp b/clang/test/SemaSYCL/check-work-group-size-hint-device.cpp
index 6737fe7f2aa70..58d8a91221d19 100644
--- a/clang/test/SemaSYCL/check-work-group-size-hint-device.cpp
+++ b/clang/test/SemaSYCL/check-work-group-size-hint-device.cpp
@@ -101,7 +101,7 @@ class Functor16x2x1 {
 
 class Functor4x4x4 {
 public:
-  [[sycl::work_group_size_hint(4, 4, 4)]] void operator()() const {}; // expected-warning {{'work_group_size_hint' attribute can only be applied to a SYCL kernel function}}
+  [[sycl::work_group_size_hint(4, 4, 4)]] void operator()() const {};
 };
 
 // Checking whether propagation of the attribute happens or not, according to the SYCL version.
diff --git a/clang/test/SemaSYCL/reqd_work_group_size.cpp b/clang/test/SemaSYCL/reqd_work_group_size.cpp
index a2d2760480117..7c92ca7276e3e 100644
--- a/clang/test/SemaSYCL/reqd_work_group_size.cpp
+++ b/clang/test/SemaSYCL/reqd_work_group_size.cpp
@@ -37,16 +37,14 @@ f4() {}
 // Catch the easy case where the attributes are all specified at once with
 // different arguments.
 struct TRIFuncObjGood1 {
-  // expected-note@+3 {{previous attribute is here}}
-  // expected-error@+2 {{attribute 'reqd_work_group_size' is already applied with different arguments}}
-  // expected-warning@+1 {{'reqd_work_group_size' attribute can only be applied to a SYCL kernel function}} 
+  // expected-note@+2 {{previous attribute is here}}
+  // expected-error@+1 {{attribute 'reqd_work_group_size' is already applied with different arguments}}
   [[sycl::reqd_work_group_size(64)]] [[sycl::reqd_work_group_size(128)]] void operator()() const {}
 };
 
 struct TRIFuncObjGood2 {
-  // expected-note@+3 {{previous attribute is here}}
-  // expected-error@+2 {{attribute 'reqd_work_group_size' is already applied with different arguments}}
-  // expected-warning@+1 {{'reqd_work_group_size' attribute can only be applied to a SYCL kernel function}}
+  // expected-note@+2 {{previous attribute is here}}
+  // expected-error@+1 {{attribute 'reqd_work_group_size' is already applied with different arguments}}
   [[sycl::reqd_work_group_size(64, 64)]] [[sycl::reqd_work_group_size(128, 128)]] void operator()() const {}
 };
 
@@ -55,8 +53,7 @@ struct TRIFuncObjGood3 {
   operator()() const;
 };
 
-[[sycl::reqd_work_group_size(4, 4)]] // expected-error {{attribute 'reqd_work_group_size' is already applied with different arguments}} \
-// expected-warning {{'reqd_work_group_size' attribute can only be applied to a SYCL kernel function}}
+[[sycl::reqd_work_group_size(4, 4)]] // expected-error {{attribute 'reqd_work_group_size' is already applied with different arguments}}
 void
 TRIFuncObjGood3::operator()() const {}
 
@@ -77,7 +74,7 @@ class FunctorC {
 
 class Functor32 {
 public:
-  [[sycl::reqd_work_group_size(32, 1, 1)]]      // expected-note {{previous attribute is here}} // expected-warning {{'reqd_work_group_size' attribute can only be applied to a SYCL kernel function}}
+  [[sycl::reqd_work_group_size(32, 1, 1)]]      // expected-note {{previous attribute is here}}
   [[sycl::reqd_work_group_size(1, 1, 32)]] void // expected-error{{attribute 'reqd_work_group_size' is already applied with different arguments}}
   operator()() const {}
 };
@@ -143,8 +140,7 @@ struct TRIFuncObjBad {
   operator()() const;
 };
 
-[[sycl::reqd_work_group_size(1, 1, 32)]] // expected-error {{attribute 'reqd_work_group_size' is already applied with different arguments}} \
-// expected-warning {{'reqd_work_group_size' attribute can only be applied to a SYCL kernel function}}
+[[sycl::reqd_work_group_size(1, 1, 32)]] // expected-error {{attribute 'reqd_work_group_size' is already applied with different arguments}}
 void
 TRIFuncObjBad::operator()() const {}
 
diff --git a/clang/test/SemaSYCL/sycl-attr-warn-non-kernel.cpp b/clang/test/SemaSYCL/sycl-attr-warn-non-kernel.cpp
index c4ff35d6e02db..8c243081a9407 100644
--- a/clang/test/SemaSYCL/sycl-attr-warn-non-kernel.cpp
+++ b/clang/test/SemaSYCL/sycl-attr-warn-non-kernel.cpp
@@ -26,7 +26,7 @@ void Functor16::operator()() const {
 
 class Functor16x16 {
 public:
-  [[sycl::reqd_work_group_size(16,16)]] void operator()() const; // expected-warning {{'reqd_work_group_size' attribute can only be applied to a SYCL kernel function}}
+  [[sycl::reqd_work_group_size(16,16)]] void operator()() const; 
 };
 void Functor16x16::operator()() const {
 }
@@ -41,7 +41,7 @@ class Functor16x16x16 {
 
 class FunctorSubGroupSize4 {
 public:
-  [[intel::reqd_sub_group_size(4)]] void operator()() const{}  // expected-warning {{'reqd_sub_group_size' attribute can only be applied to a SYCL kernel function}}
+  [[intel::reqd_sub_group_size(4)]] void operator()() const{}
 };
 
 class Functor8 {
@@ -49,13 +49,16 @@ class Functor8 {
   void operator()() const;  
 };
 
-[[sycl::reqd_work_group_size(8)]] void Functor8::operator()() const {} // expected-warning {{'reqd_work_group_size' attribute can only be applied to a SYCL kernel function}}
+[[sycl::reqd_work_group_size(8)]] void Functor8::operator()() const {}
 
 int main() {
   sycl::queue q;
-  Functor16x16 f16x16;
-  FunctorSubGroupSize4 fs4;
+
+  // Show that the functors don't issue diagnostics.
   Functor8 f8;
+  FunctorSubGroupSize4 fs4;
+  Functor16x16 f16x16;
+  Functor16x16x16 f16x16x16;
   
   q.submit([&](sycl::handler& h) {
     h.single_task<class kernel_name>(
@@ -65,14 +68,5 @@ int main() {
     );
   });
 
-
-  q.submit([&](sycl::handler &h) {
-    Functor16 f16;
-    Functor16x16x16 f16x16x16;
-    h.single_task<class kernel_name1>(f16);  // OK attribute reqd_work_group_size applied to kernel
-    h.single_task<class kernel_name2>(f16x16x16); // OK attribute reqd_work_group_size applied to kernel
-  });
-
-
   return 0;
 }