diff --git a/m/common/base.nix b/m/common/base.nix
index cdd1dc19..ba53802e 100644
--- a/m/common/base.nix
+++ b/m/common/base.nix
@@ -11,6 +11,7 @@
     ./base/hw.nix
     ./base/net.nix
     ./base/nix.nix
+    ./base/sys-devices.nix
     ./base/ntp.nix
     ./base/rev.nix
     ./base/ssh.nix
diff --git a/m/common/base/sys-devices.nix b/m/common/base/sys-devices.nix
new file mode 100644
index 00000000..414d8b66
--- /dev/null
+++ b/m/common/base/sys-devices.nix
@@ -0,0 +1,9 @@
+{
+  nix.settings.system-features = [ "sys-devices" ];
+
+  programs.nix-required-mounts.enable = true;
+  programs.nix-required-mounts.allowedPatterns.sys-devices.paths = [
+    "/sys/devices/system/cpu"
+    "/sys/devices/system/node"
+  ];
+}
diff --git a/overlay.nix b/overlay.nix
index 6d2af14b..d54ea481 100644
--- a/overlay.nix
+++ b/overlay.nix
@@ -62,7 +62,7 @@ let
   };
 
   tests = rec {
-    #hwloc = callPackage ./test/bugs/hwloc.nix { }; # Broken, no /sys
+    hwloc = callPackage ./test/bugs/hwloc.nix { };
     #sigsegv = callPackage ./test/reproducers/sigsegv.nix { };
     hello-c = callPackage ./test/compilers/hello-c.nix { };
     hello-cpp = callPackage ./test/compilers/hello-cpp.nix { };
diff --git a/test/bugs/hwloc.nix b/test/bugs/hwloc.nix
index 2546d3d6..8dd73d37 100644
--- a/test/bugs/hwloc.nix
+++ b/test/bugs/hwloc.nix
@@ -6,6 +6,7 @@
 
 stdenv.mkDerivation {
   name = "hwloc-test";
+  requiredSystemFeatures = [ "sys-devices" ];
 
   src = ./.;
 
@@ -14,7 +15,7 @@ stdenv.mkDerivation {
   buildPhase = ''
     ls -l /sys
     gcc -lhwloc hwloc.c -o hwloc
-    strace ./hwloc
+    strace ./hwloc > $out
   '';
 
 }
diff --git a/test/compilers/clang-openmp-ld.nix b/test/compilers/clang-openmp-ld.nix
index 593706a9..1b9f0bb2 100644
--- a/test/compilers/clang-openmp-ld.nix
+++ b/test/compilers/clang-openmp-ld.nix
@@ -23,9 +23,8 @@ in stdenv.mkDerivation {
   dontUnpack = true;
   dontConfigure = true;
 
-  # nOS-V requires access to /sys/devices to request NUMA information. It will
-  # fail to run otherwise, so we disable the sandbox for this test.
-  __noChroot = true;
+  # nOS-V requires access to /sys/devices to request NUMA information
+  requiredSystemFeatures = [ "sys-devices" ];
 
   buildInputs = [ openmp ];
 
diff --git a/test/compilers/clang-openmp-nosv.nix b/test/compilers/clang-openmp-nosv.nix
index 237e4666..67b8189d 100644
--- a/test/compilers/clang-openmp-nosv.nix
+++ b/test/compilers/clang-openmp-nosv.nix
@@ -36,9 +36,8 @@ in stdenv.mkDerivation {
   dontUnpack = true;
   dontConfigure = true;
 
-  # nOS-V requires access to /sys/devices to request NUMA information. It will
-  # fail to run otherwise, so we disable the sandbox for this test.
-  __noChroot = true;
+  # nOS-V requires access to /sys/devices to request NUMA information
+  requiredSystemFeatures = [ "sys-devices" ];
 
   buildInputs = [ nosv ];
 
diff --git a/test/compilers/clang-openmp.nix b/test/compilers/clang-openmp.nix
index 42044c75..e0833c09 100644
--- a/test/compilers/clang-openmp.nix
+++ b/test/compilers/clang-openmp.nix
@@ -24,9 +24,8 @@ in stdenv.mkDerivation {
   dontUnpack = true;
   dontConfigure = true;
 
-  # nOS-V requires access to /sys/devices to request NUMA information. It will
-  # fail to run otherwise, so we disable the sandbox for this test.
-  __noChroot = true;
+  # nOS-V requires access to /sys/devices to request NUMA information
+  requiredSystemFeatures = [ "sys-devices" ];
 
   buildPhase = ''
     set -x
diff --git a/test/compilers/ompss2.nix b/test/compilers/ompss2.nix
index 9ce3728f..60d68f32 100644
--- a/test/compilers/ompss2.nix
+++ b/test/compilers/ompss2.nix
@@ -25,9 +25,10 @@ stdenv.mkDerivation rec {
   hardeningDisable = [ "all" ];
   #NIX_DEBUG = 1;
   buildInputs = [ ]; #strace gdb;
-  # NODES requires access to /sys/devices to request NUMA information. It will
-  # fail to run otherwise, so we disable the sandbox for this test.
-  __noChroot = true;
+
+  # NODES requires access to /sys/devices to request NUMA information
+  requiredSystemFeatures = [ "sys-devices" ];
+
   buildPhase = ''
     set -x
     #$CC -v