diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,8 +1,12 @@
 # Revision history for cgroup-rts-threads
 
+## 0.2.1.1
+
+- Adds tests files to sdist
+
 ## 0.2.1.0
 
-- Support configuring the rounding mode for the CPU quota to capabilities conversion
+- Adds 'initRTSThreadsWith', which allows for changing the rounding behavior when computing the number of capabilities to use
 
 ## 0.2.0.0
 
diff --git a/cgroup-rts-threads.cabal b/cgroup-rts-threads.cabal
--- a/cgroup-rts-threads.cabal
+++ b/cgroup-rts-threads.cabal
@@ -1,6 +1,6 @@
 cabal-version:      3.0
 name:               cgroup-rts-threads
-version:            0.2.1.0
+version:            0.2.1.1
 synopsis:
   A container-/cgroup-aware substitute for the GHC RTS `-N` flag
 
@@ -18,6 +18,18 @@
 extra-source-files:
   CHANGELOG.md
   README.md
+  test/System/CGroup/**/*.max
+  test/System/CGroup/**/*.cfs_period_us
+  test/System/CGroup/**/*.cfs_quota_us
+  test/System/CGroup/V1/testdata-controller/direct/mountinfo
+  test/System/CGroup/V1/testdata-controller/indirect/cgroup
+  test/System/CGroup/V1/testdata-controller/indirect/mountinfo
+  test/System/CGroup/V1/testdata-controller/realworld/cgroup
+  test/System/CGroup/V1/testdata-controller/realworld/mountinfo
+  test/System/CGroup/V2/testdata-cgroup/nested/cgroup
+  test/System/CGroup/V2/testdata-cgroup/nested/mountinfo
+  test/System/CGroup/V2/testdata-cgroup/root/cgroup
+  test/System/CGroup/V2/testdata-cgroup/root/mountinfo
 
 source-repository head
   type:     git
diff --git a/test/System/CGroup/V1/testdata-controller/direct/mountinfo b/test/System/CGroup/V1/testdata-controller/direct/mountinfo
new file mode 100644
--- /dev/null
+++ b/test/System/CGroup/V1/testdata-controller/direct/mountinfo
@@ -0,0 +1,1 @@
+630 628 0:31 /docker/9a727716c6193036fa661c0bbe254354036e130905cbbd6c69568b26df684b1d /sys/fs/cgroup/cpu ro,nosuid,nodev,noexec,relatime master:19 - cgroup cpu rw,cpu
diff --git a/test/System/CGroup/V1/testdata-controller/indirect/cgroup b/test/System/CGroup/V1/testdata-controller/indirect/cgroup
new file mode 100644
--- /dev/null
+++ b/test/System/CGroup/V1/testdata-controller/indirect/cgroup
@@ -0,0 +1,1 @@
+2:cpu:/docker/9a727716c6193036fa661c0bbe254354036e130905cbbd6c69568b26df684b1d/subdir
diff --git a/test/System/CGroup/V1/testdata-controller/indirect/mountinfo b/test/System/CGroup/V1/testdata-controller/indirect/mountinfo
new file mode 100644
--- /dev/null
+++ b/test/System/CGroup/V1/testdata-controller/indirect/mountinfo
@@ -0,0 +1,1 @@
+630 628 0:31 /docker/9a727716c6193036fa661c0bbe254354036e130905cbbd6c69568b26df684b1d /sys/fs/cgroup/cpu ro,nosuid,nodev,noexec,relatime master:19 - cgroup cpu rw,cpu
diff --git a/test/System/CGroup/V1/testdata-controller/realworld/cgroup b/test/System/CGroup/V1/testdata-controller/realworld/cgroup
new file mode 100644
--- /dev/null
+++ b/test/System/CGroup/V1/testdata-controller/realworld/cgroup
@@ -0,0 +1,14 @@
+14:name=systemd:/docker/9a727716c6193036fa661c0bbe254354036e130905cbbd6c69568b26df684b1d
+13:rdma:/
+12:pids:/docker/9a727716c6193036fa661c0bbe254354036e130905cbbd6c69568b26df684b1d
+11:hugetlb:/docker/9a727716c6193036fa661c0bbe254354036e130905cbbd6c69568b26df684b1d
+10:net_prio:/docker/9a727716c6193036fa661c0bbe254354036e130905cbbd6c69568b26df684b1d
+9:perf_event:/docker/9a727716c6193036fa661c0bbe254354036e130905cbbd6c69568b26df684b1d
+8:net_cls:/docker/9a727716c6193036fa661c0bbe254354036e130905cbbd6c69568b26df684b1d
+7:freezer:/docker/9a727716c6193036fa661c0bbe254354036e130905cbbd6c69568b26df684b1d
+6:devices:/docker/9a727716c6193036fa661c0bbe254354036e130905cbbd6c69568b26df684b1d
+5:memory:/docker/9a727716c6193036fa661c0bbe254354036e130905cbbd6c69568b26df684b1d
+4:blkio:/docker/9a727716c6193036fa661c0bbe254354036e130905cbbd6c69568b26df684b1d
+3:cpuacct:/docker/9a727716c6193036fa661c0bbe254354036e130905cbbd6c69568b26df684b1d
+2:cpu:/docker/9a727716c6193036fa661c0bbe254354036e130905cbbd6c69568b26df684b1d
+1:cpuset:/docker/9a727716c6193036fa661c0bbe254354036e130905cbbd6c69568b26df684b1d
diff --git a/test/System/CGroup/V1/testdata-controller/realworld/mountinfo b/test/System/CGroup/V1/testdata-controller/realworld/mountinfo
new file mode 100644
--- /dev/null
+++ b/test/System/CGroup/V1/testdata-controller/realworld/mountinfo
@@ -0,0 +1,8 @@
+623 434 0:161 / / rw,relatime master:161 - overlay overlay rw,lowerdir=/var/lib/docker/overlay2/l/4HCB7FKXGOKVFG5LMB7MJEAMJ4:/var/lib/docker/overlay2/l/FSMEFB6672AAE6ANGEPMIFDZAQ:/var/lib/docker/overlay2/l/OOXJX3PUF6D2LLFT2SYKGQMYWV:/var/lib/docker/overlay2/l/T5FNCAQTEANVA5TYAVXIMHB37W:/var/lib/docker/overlay2/l/XUL6EMIUAIGC5UXJ2UVXAJ6EU5:/var/lib/docker/overlay2/l/U6KL2F5A2HXKJCRWATE4J37NXX:/var/lib/docker/overlay2/l/RU2BMNWGFSX653UD3UXXA52UHS,upperdir=/var/lib/docker/overlay2/bbad75edc1476c2258a545cd3afd00d912e73360535a258c35ff7ab3aaea04eb/diff,workdir=/var/lib/docker/overlay2/bbad75edc1476c2258a545cd3afd00d912e73360535a258c35ff7ab3aaea04eb/work
+624 623 0:164 / /proc rw,nosuid,nodev,noexec,relatime - proc proc rw
+625 623 0:165 / /dev rw,nosuid - tmpfs tmpfs rw,size=65536k,mode=755
+626 625 0:166 / /dev/pts rw,nosuid,noexec,relatime - devpts devpts rw,gid=5,mode=620,ptmxmode=666
+627 623 0:167 / /sys ro,nosuid,nodev,noexec,relatime - sysfs sysfs ro
+628 627 0:168 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,mode=755
+629 628 0:30 /docker/9a727716c6193036fa661c0bbe254354036e130905cbbd6c69568b26df684b1d /sys/fs/cgroup/cpuset ro,nosuid,nodev,noexec,relatime master:18 - cgroup cpuset rw,cpuset
+630 628 0:31 /docker/9a727716c6193036fa661c0bbe254354036e130905cbbd6c69568b26df684b1d /sys/fs/cgroup/cpu ro,nosuid,nodev,noexec,relatime master:19 - cgroup cpu rw,cpu
diff --git a/test/System/CGroup/V1/testdata-cpu/noquota/cpu.cfs_period_us b/test/System/CGroup/V1/testdata-cpu/noquota/cpu.cfs_period_us
new file mode 100644
--- /dev/null
+++ b/test/System/CGroup/V1/testdata-cpu/noquota/cpu.cfs_period_us
@@ -0,0 +1,1 @@
+100000
diff --git a/test/System/CGroup/V1/testdata-cpu/noquota/cpu.cfs_quota_us b/test/System/CGroup/V1/testdata-cpu/noquota/cpu.cfs_quota_us
new file mode 100644
--- /dev/null
+++ b/test/System/CGroup/V1/testdata-cpu/noquota/cpu.cfs_quota_us
@@ -0,0 +1,1 @@
+-1
diff --git a/test/System/CGroup/V1/testdata-cpu/quota/cpu.cfs_period_us b/test/System/CGroup/V1/testdata-cpu/quota/cpu.cfs_period_us
new file mode 100644
--- /dev/null
+++ b/test/System/CGroup/V1/testdata-cpu/quota/cpu.cfs_period_us
@@ -0,0 +1,1 @@
+2
diff --git a/test/System/CGroup/V1/testdata-cpu/quota/cpu.cfs_quota_us b/test/System/CGroup/V1/testdata-cpu/quota/cpu.cfs_quota_us
new file mode 100644
--- /dev/null
+++ b/test/System/CGroup/V1/testdata-cpu/quota/cpu.cfs_quota_us
@@ -0,0 +1,1 @@
+1
diff --git a/test/System/CGroup/V2/testdata-cgroup/nested/cgroup b/test/System/CGroup/V2/testdata-cgroup/nested/cgroup
new file mode 100644
--- /dev/null
+++ b/test/System/CGroup/V2/testdata-cgroup/nested/cgroup
@@ -0,0 +1,1 @@
+0::/some/nested/cgroup
diff --git a/test/System/CGroup/V2/testdata-cgroup/nested/mountinfo b/test/System/CGroup/V2/testdata-cgroup/nested/mountinfo
new file mode 100644
--- /dev/null
+++ b/test/System/CGroup/V2/testdata-cgroup/nested/mountinfo
@@ -0,0 +1,1 @@
+32 23 0:27 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime shared:9 - cgroup2 cgroup2 rw,nsdelegate,memory_recursiveprot
diff --git a/test/System/CGroup/V2/testdata-cgroup/root/cgroup b/test/System/CGroup/V2/testdata-cgroup/root/cgroup
new file mode 100644
--- /dev/null
+++ b/test/System/CGroup/V2/testdata-cgroup/root/cgroup
@@ -0,0 +1,1 @@
+0::/
diff --git a/test/System/CGroup/V2/testdata-cgroup/root/mountinfo b/test/System/CGroup/V2/testdata-cgroup/root/mountinfo
new file mode 100644
--- /dev/null
+++ b/test/System/CGroup/V2/testdata-cgroup/root/mountinfo
@@ -0,0 +1,1 @@
+32 23 0:27 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime shared:9 - cgroup2 cgroup2 rw,nsdelegate,memory_recursiveprot
diff --git a/test/System/CGroup/V2/testdata-cpu/limited/bigger/cpu.max b/test/System/CGroup/V2/testdata-cpu/limited/bigger/cpu.max
new file mode 100644
--- /dev/null
+++ b/test/System/CGroup/V2/testdata-cpu/limited/bigger/cpu.max
@@ -0,0 +1,1 @@
+80000 100000
diff --git a/test/System/CGroup/V2/testdata-cpu/limited/cpu.max b/test/System/CGroup/V2/testdata-cpu/limited/cpu.max
new file mode 100644
--- /dev/null
+++ b/test/System/CGroup/V2/testdata-cpu/limited/cpu.max
@@ -0,0 +1,1 @@
+2000 10000
diff --git a/test/System/CGroup/V2/testdata-cpu/limited/unlimited/cpu.max b/test/System/CGroup/V2/testdata-cpu/limited/unlimited/cpu.max
new file mode 100644
--- /dev/null
+++ b/test/System/CGroup/V2/testdata-cpu/limited/unlimited/cpu.max
@@ -0,0 +1,1 @@
+max 2000
diff --git a/test/System/CGroup/V2/testdata-cpu/max/cpu.max b/test/System/CGroup/V2/testdata-cpu/max/cpu.max
new file mode 100644
--- /dev/null
+++ b/test/System/CGroup/V2/testdata-cpu/max/cpu.max
@@ -0,0 +1,1 @@
+max 100000
