diff --git a/src/dft/backends/cufft/descriptor.cpp b/src/dft/backends/cufft/descriptor.cpp
index d102164c2..bf26b600f 100644
--- a/src/dft/backends/cufft/descriptor.cpp
+++ b/src/dft/backends/cufft/descriptor.cpp
@@ -22,9 +22,7 @@
 
 #include "oneapi/mkl/dft/detail/cufft/onemkl_dft_cufft.hpp"
 
-namespace oneapi {
-namespace mkl {
-namespace dft {
+namespace oneapi::mkl::dft::detail {
 
 template <precision prec, domain dom>
 void descriptor<prec, dom>::commit(backend_selector<backend::cufft> selector) {
@@ -44,6 +42,4 @@ template void descriptor<precision::DOUBLE, domain::COMPLEX>::commit(
     backend_selector<backend::cufft>);
 template void descriptor<precision::DOUBLE, domain::REAL>::commit(backend_selector<backend::cufft>);
 
-} //namespace dft
-} //namespace mkl
-} //namespace oneapi
+} //namespace oneapi::mkl::dft::detail
diff --git a/src/dft/backends/descriptor.cpp b/src/dft/backends/descriptor.cpp
index aa4cded9c..c6f6884f8 100644
--- a/src/dft/backends/descriptor.cpp
+++ b/src/dft/backends/descriptor.cpp
@@ -22,9 +22,7 @@
 
 #include "../descriptor.cxx"
 
-namespace oneapi {
-namespace mkl {
-namespace dft {
+namespace oneapi::mkl::dft::detail {
 
 template <precision prec, domain dom>
 void descriptor<prec, dom>::commit(sycl::queue &queue) {
@@ -41,6 +39,4 @@ template void descriptor<precision::SINGLE, domain::REAL>::commit(sycl::queue &)
 template void descriptor<precision::DOUBLE, domain::COMPLEX>::commit(sycl::queue &);
 template void descriptor<precision::DOUBLE, domain::REAL>::commit(sycl::queue &);
 
-} //namespace dft
-} //namespace mkl
-} //namespace oneapi
+} //namespace oneapi::mkl::dft::detail
diff --git a/src/dft/backends/mklcpu/descriptor.cpp b/src/dft/backends/mklcpu/descriptor.cpp
index 2bb0e2835..a72fdcfc3 100644
--- a/src/dft/backends/mklcpu/descriptor.cpp
+++ b/src/dft/backends/mklcpu/descriptor.cpp
@@ -22,9 +22,7 @@
 
 #include "oneapi/mkl/dft/detail/mklcpu/onemkl_dft_mklcpu.hpp"
 
-namespace oneapi {
-namespace mkl {
-namespace dft {
+namespace oneapi::mkl::dft::detail {
 
 template <precision prec, domain dom>
 void descriptor<prec, dom>::commit(backend_selector<backend::mklcpu> selector) {
@@ -46,6 +44,4 @@ template void descriptor<precision::DOUBLE, domain::COMPLEX>::commit(
 template void descriptor<precision::DOUBLE, domain::REAL>::commit(
     backend_selector<backend::mklcpu>);
 
-} //namespace dft
-} //namespace mkl
-} //namespace oneapi
+} //namespace oneapi::mkl::dft::detail
diff --git a/src/dft/backends/mklgpu/descriptor.cpp b/src/dft/backends/mklgpu/descriptor.cpp
index d2d2fee7a..7f7f0bf70 100644
--- a/src/dft/backends/mklgpu/descriptor.cpp
+++ b/src/dft/backends/mklgpu/descriptor.cpp
@@ -22,9 +22,7 @@
 
 #include "oneapi/mkl/dft/detail/mklgpu/onemkl_dft_mklgpu.hpp"
 
-namespace oneapi {
-namespace mkl {
-namespace dft {
+namespace oneapi::mkl::dft::detail {
 
 template <precision prec, domain dom>
 void descriptor<prec, dom>::commit(backend_selector<backend::mklgpu> selector) {
@@ -46,6 +44,4 @@ template void descriptor<precision::DOUBLE, domain::COMPLEX>::commit(
 template void descriptor<precision::DOUBLE, domain::REAL>::commit(
     backend_selector<backend::mklgpu>);
 
-} //namespace dft
-} //namespace mkl
-} //namespace oneapi
+} //namespace oneapi::mkl::dft::detail
diff --git a/src/dft/backends/portfft/descriptor.cpp b/src/dft/backends/portfft/descriptor.cpp
index d72d23bb5..c45b9f2c5 100644
--- a/src/dft/backends/portfft/descriptor.cpp
+++ b/src/dft/backends/portfft/descriptor.cpp
@@ -22,7 +22,7 @@
 
 #include "oneapi/mkl/dft/detail/portfft/onemkl_dft_portfft.hpp"
 
-namespace oneapi::mkl::dft {
+namespace oneapi::mkl::dft::detail {
 
 template <precision prec, domain dom>
 void descriptor<prec, dom>::commit(backend_selector<backend::portfft> selector) {
@@ -44,4 +44,4 @@ template void descriptor<precision::DOUBLE, domain::COMPLEX>::commit(
 template void descriptor<precision::DOUBLE, domain::REAL>::commit(
     backend_selector<backend::portfft>);
 
-} // namespace oneapi::mkl::dft
+} // namespace oneapi::mkl::dft::detail
diff --git a/src/dft/backends/rocfft/descriptor.cpp b/src/dft/backends/rocfft/descriptor.cpp
index 83fdbe1dc..22f21590a 100644
--- a/src/dft/backends/rocfft/descriptor.cpp
+++ b/src/dft/backends/rocfft/descriptor.cpp
@@ -22,9 +22,7 @@
 
 #include "oneapi/mkl/dft/detail/rocfft/onemkl_dft_rocfft.hpp"
 
-namespace oneapi {
-namespace mkl {
-namespace dft {
+namespace oneapi::mkl::dft::detail {
 
 template <precision prec, domain dom>
 void descriptor<prec, dom>::commit(backend_selector<backend::rocfft> selector) {
@@ -46,6 +44,4 @@ template void descriptor<precision::DOUBLE, domain::COMPLEX>::commit(
 template void descriptor<precision::DOUBLE, domain::REAL>::commit(
     backend_selector<backend::rocfft>);
 
-} //namespace dft
-} //namespace mkl
-} //namespace oneapi
+} //namespace oneapi::mkl::dft::detail