diff --git a/libcontainer/cgroups/systemd/v1.go b/libcontainer/cgroups/systemd/v1.go
index a805f72c..5d324133 100644
--- a/libcontainer/cgroups/systemd/v1.go
+++ b/libcontainer/cgroups/systemd/v1.go
@@ -125,7 +125,7 @@ func genV1ResourcesProperties(c *configs.Cgroup) ([]systemdDbus.Property, error)
 			newProp("BlockIOWeight", uint64(c.Resources.BlkioWeight)))
 	}
 
-	if c.Resources.PidsLimit > 0 {
+	if c.Resources.PidsLimit > 0 || c.Resources.PidsLimit == -1 {
 		properties = append(properties,
 			newProp("TasksAccounting", true),
 			newProp("TasksMax", uint64(c.Resources.PidsLimit)))
diff --git a/libcontainer/cgroups/systemd/v2.go b/libcontainer/cgroups/systemd/v2.go
index b929e880..2fcf312a 100644
--- a/libcontainer/cgroups/systemd/v2.go
+++ b/libcontainer/cgroups/systemd/v2.go
@@ -92,7 +92,7 @@ func genV2ResourcesProperties(c *configs.Cgroup) ([]systemdDbus.Property, error)
 			newProp("CPUQuotaPerSecUSec", cpuQuotaPerSecUSec))
 	}
 
-	if c.Resources.PidsLimit > 0 {
+	if c.Resources.PidsLimit > 0 || c.Resources.PidsLimit == -1 {
 		properties = append(properties,
 			newProp("TasksAccounting", true),
 			newProp("TasksMax", uint64(c.Resources.PidsLimit)))
diff --git a/tests/integration/update.bats b/tests/integration/update.bats
index ca47f850..76d931f5 100644
--- a/tests/integration/update.bats
+++ b/tests/integration/update.bats
@@ -161,6 +161,12 @@ EOF
     check_cgroup_value "pids.max" 10
     check_systemd_value "TasksMax" 10
 
+    # unlimited
+    runc update test_update --pids-limit -1
+    [ "$status" -eq 0 ]
+    check_cgroup_value "pids.max" max
+    check_systemd_value "TasksMax" $SD_UNLIMITED
+
     # Revert to the test initial value via json on stdin
     runc update  -r - test_update <<EOF
 {