diff --git a/src/pyinfra/facts/server.py b/src/pyinfra/facts/server.py
index 7ff7c86cd..6ca2a6ed8 100644
--- a/src/pyinfra/facts/server.py
+++ b/src/pyinfra/facts/server.py
@@ -459,7 +459,7 @@ def process(self, output):
                 key = key.strip()
                 values = values.strip()
 
-                if re.match(r"^[a-zA-Z0-9_\.\s]+$", values):
+                if re.match(r"^[a-zA-Z0-9_\-\.\s]+$", values):
                     values = [try_int(item.strip()) for item in values.split()]
 
                     if len(values) == 1:
diff --git a/tests/facts/server.Sysctl/sysctl_linux.json b/tests/facts/server.Sysctl/sysctl_linux.json
index f7b77c59c..7141366cb 100644
--- a/tests/facts/server.Sysctl/sysctl_linux.json
+++ b/tests/facts/server.Sysctl/sysctl_linux.json
@@ -1,12 +1,14 @@
 {
     "command": "sysctl -a",
     "output": [
+        "net.ipv4.tcp_adv_win_scale = -2",
         "vm.nr_hugepages_mempolicy = 0",
         "nope what",
         "vm.nr_overcommit_hugepages = 0"
     ],
     "fact": {
+        "net.ipv4.tcp_adv_win_scale": -2,
         "vm.nr_hugepages_mempolicy": 0,
         "vm.nr_overcommit_hugepages": 0
     }
-}
+}
\ No newline at end of file