diff --git a/toolchains/intel-2021_10_0-impi-2021_10_0/spack.yaml.jinja b/toolchains/intel-2021_10_0-impi-2021_10_0/spack.yaml.jinja
index b702267fcefd7a2873d697f45ccca2de48035879..35b818fa36870c24eb8a4f68928f4888e4262914 100644
--- a/toolchains/intel-2021_10_0-impi-2021_10_0/spack.yaml.jinja
+++ b/toolchains/intel-2021_10_0-impi-2021_10_0/spack.yaml.jinja
@@ -16,12 +16,12 @@ spack:
     - sparskit@develop
     - nlopt@2.7.1
     - libgd@2.3.3
-    - python@3.11.7
+    - python@3.11.4
     - cgal@5.6
     - dftbplus@23.1~arpack~gpu~mpi~sockets~transport+api+shared~openmp
     - perl-yaml@1.30
   - packages_with_mpi:
-    - intel-oneapi-mkl@2023.2.0+cluster threads=openmp ^intel-oneapi-tbb
+    - intel-oneapi-mkl
     - elpa@2023.11.001-patched+openmp
     - elpa@2023.11.001-patched~openmp
     - parmetis@4.0.3+int64
@@ -43,9 +43,16 @@ spack:
   packages:
     all:
       require: "%{{ fallback_compiler }}"
+    blas:
+      require: "intel-oneapi-mkl"
+    lapack:
+      require: "intel-oneapi-mkl"
+    cmake:
+      require: "@3.23.6"
+    ninja:
+      require: "@1.11.1"
     boost:
-      version: [1.84.0]
-      require: "%{{ toolchain_compiler }}"
+      require: "@1.84.0%{{ toolchain_compiler }}"
     gsl:
       require: "%{{ toolchain_compiler }}"
     sparskit:
@@ -83,7 +90,7 @@ spack:
     parmetis:
       require: "%{{ toolchain_compiler }}"
     intel-oneapi-mkl:
-      require: "%{{ toolchain_compiler }}"
+      require: "@2023.2.0%{{ toolchain_compiler }}+cluster threads=openmp ^intel-oneapi-tbb"
     intel-oneapi-tbb:
       require: "%{{ toolchain_compiler }}"
     intel-tbb:
diff --git a/toolchains/intel-2021_10_0/spack.yaml.jinja b/toolchains/intel-2021_10_0/spack.yaml.jinja
index bcf73edae5fd4d22dbea3e40c7fb3f9f6547cd4e..7b9221b16453c3b41f45d3151c8c3bce96a76166 100644
--- a/toolchains/intel-2021_10_0/spack.yaml.jinja
+++ b/toolchains/intel-2021_10_0/spack.yaml.jinja
@@ -6,7 +6,7 @@ spack:
   - automake@1.16.5
   - cmake
   - ninja
-  - intel-oneapi-mkl@2023.2.0 threads=openmp
+  - intel-oneapi-mkl
   # octopus dependencies:
   - libxc@6.2.2+kxc
   - spglib@2.1.0
@@ -15,7 +15,7 @@ spack:
   - nlopt@2.7.1
   - libgd@2.3.3
   - cgal@5.6
-  - python@3.11.7
+  - python@3.11.4
   - hdf5@1.14.3~mpi
   - netcdf-fortran@4.6.1 ^netcdf-c~~mpi
   - etsf-io@1.0.4
@@ -25,18 +25,21 @@ spack:
   - perl-yaml@1.30
   view: false
   concretizer:
-    unify: true
+    unify: when_possible
     reuse: false
   packages:
     all:
       require: "%{{ fallback_compiler }}"
+    blas:
+      require: "intel-oneapi-mkl"
+    lapack:
+      require: "intel-oneapi-mkl"
     cmake:
-      version: [3.26.6]
+      require: "@3.23.6"
     ninja:
-      version: [1.11.1]
+      require: "@1.11.1"
     boost:
-      version: [1.84.0]
-      require: "%{{ toolchain_compiler }}"
+      require: "@1.84.0%{{ toolchain_compiler }}"
     gsl:
       require: "%{{ toolchain_compiler }}"
     sparskit:
@@ -70,7 +73,7 @@ spack:
     parmetis:
       require: "%{{ toolchain_compiler }}"
     intel-oneapi-mkl:
-      require: "%{{ toolchain_compiler }}"
+      require: "@2023.2.0%{{ toolchain_compiler }} threads=openmp"
     intel-oneapi-tbb:
       require: "%{{ toolchain_compiler }}"
     intel-tbb: