diff --git a/EM/relion/build b/EM/relion/build
index e4e5da2..22c5302 100755
--- a/EM/relion/build
+++ b/EM/relion/build
@@ -4,7 +4,6 @@ pbuild::add_to_group 'EM'
 pbuild::use_cmake
 
 pbuild::prep() {
-
     local BRANCH
     if [[ "$V" =~ beta$ ]]; then
         BRANCH="ver${V_MAJOR}.${V_MINOR}"
@@ -16,15 +15,28 @@ pbuild::prep() {
 }
 
 pbuild::pre_configure() {
-    pbuild::add_configure_args FORCE_OWN_FFTW=ON
-    pbuild::add_configure_args FORCE_OWN_FLTK=ON
-    pbuild::add_configure_args CUDA=ON
-    pbuild::add_configure_args CudaTexture=ON
-    pbuild::add_configure_args ALTCPU=ON
-    pbuild::add_configure_args FORCE_OWN_TBB=ON
+    # CMake-based build
+
+    pbuild::add_configure_args "-DFORCE_OWN_FFTW=ON"
+    pbuild::add_configure_args "-DFORCE_OWN_FLTK=ON"
+    pbuild::add_configure_args "-DFORCE_OWN_TBB=ON"
+
+    # CUDA related (set lowest CC to 6.1 for 1080 compatibility)
+    pbuild::add_configure_args "-DCUDA=ON"
+    pbuild::add_configure_args "-DCUDA_ARCH=61"
+    pbuild::add_configure_args "-DCudaTexture=ON"
+    
+    # Since ver3.0 relion cannot have ALTCPU and CUDA activated
+    # at the same time. Otherwise the configuration exits with
+    # an error.
+    if [[ "$V_MAJOR" -le "3" ]]; then
+        pbuild::add_configure_args "-DALTCPU=ON"
+    fi
+
     if [[ -n "$INTEL_VERSION" ]]; then
         # Requires intel compiler
-        pbuild::add_configure_args MKLFFT=ON
+        pbuild::add_configure_args "-DMKLFFT=ON"
     fi
 }
 
+# vim: ts=4 sw=4 et 
diff --git a/EM/relion/files/variants b/EM/relion/files/variants
index bc42c22..100ef3b 100644
--- a/EM/relion/files/variants
+++ b/EM/relion/files/variants
@@ -11,3 +11,4 @@ relion/3.1.1-1	stable	gcc/9.2.0 openmpi/4.0.5_slurm cuda/11.0.3 b:cmake/3.15.5 b
 relion/3.1.2	stable	gcc/9.2.0 openmpi/4.0.5_slurm cuda/11.0.3 b:cmake/3.15.5 b:tiff/4.0.9 b:git/2.22.0
 relion/3.1.3	unstable	gcc/9.2.0 openmpi/4.0.5_slurm cuda/11.0.3 b:cmake/3.15.5 b:tiff/4.0.9 b:git/2.22.0
 relion/4.0-beta	unstable	gcc/9.2.0 openmpi/4.0.5_slurm cuda/11.0.3 b:cmake/3.15.5 b:tiff/4.0.9 b:git/2.22.0
+relion/4.0.0	unstable	gcc/11.2.0 openmpi/4.1.3_slurm cuda/11.5.1 b:cmake/3.23.2 b:tiff/4.3.0 b:git/2.37.0