diff --git a/changes/pr-337.md b/changes/pr-337.md
new file mode 100644
index 000000000..5c70b35ef
--- /dev/null
+++ b/changes/pr-337.md
@@ -0,0 +1 @@
+(BREAKING) Signals: rename System to Model.
diff --git a/flake.lock b/flake.lock
index be4385452..8bc5269f8 100644
--- a/flake.lock
+++ b/flake.lock
@@ -509,11 +509,11 @@
     "pysignals": {
       "flake": false,
       "locked": {
-        "lastModified": 1683346322,
-        "narHash": "sha256-8tA0TAeEx3eYU2OWQr2gptZ1kJoXVyIhw+jV9JO6ZQ4=",
+        "lastModified": 1735182553,
+        "narHash": "sha256-qOV2F0Jw5KuUICKv65uMW3aRGTWqj6Eudg3NFjEb6ts=",
         "owner": "goromal",
         "repo": "pysignals",
-        "rev": "4362eed73014ad9f0bdf1b6467033cfd35cbee21",
+        "rev": "11d6532e27122b12238af99554535f9cfb138df6",
         "type": "github"
       },
       "original": {
@@ -688,11 +688,11 @@
     "signals-cpp": {
       "flake": false,
       "locked": {
-        "lastModified": 1733642029,
-        "narHash": "sha256-aq/kiU5PxpGf+s79/xDtN+T5OuS1sjOYhqomHtIBst4=",
+        "lastModified": 1735182528,
+        "narHash": "sha256-Gj6E/vaW/xQC3pIYm1A+Zj5Rza7m2iuhA2faM1Fm1Tc=",
         "owner": "goromal",
         "repo": "signals-cpp",
-        "rev": "5a585cc69336bfda7045e341f6d1dd140a92c256",
+        "rev": "3b1cdfe2ce66f96095b762673d7ffc2ef1f666ea",
         "type": "github"
       },
       "original": {
@@ -814,11 +814,11 @@
     "trafficsim": {
       "flake": false,
       "locked": {
-        "lastModified": 1670693563,
-        "narHash": "sha256-Vk0ReIWjbhUTa/6AtPWhwgiyUF6fPvPEJSqiCfotncI=",
+        "lastModified": 1735182718,
+        "narHash": "sha256-y4kUTA5zSAj0TYRui7prBn9xBE9uhBEryZ+pYERVfBI=",
         "ref": "refs/heads/main",
-        "rev": "bd0d6741dbbd85d2951739c351dd501ac7e9af97",
-        "revCount": 5,
+        "rev": "973f3f1895ee846917bc1918be4bc6257e1d124d",
+        "revCount": 6,
         "type": "git",
         "url": "https://gist.github.com/c37629235750b65b9d0ec0e17456ee96"
       },