diff --git a/package.json b/package.json
index c552d25..2db7458 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "droidnet-command-library",
-  "version": "2.1.0",
+  "version": "2.1.1",
   "description": "Schema-driven encoder/decoder and visual composer for building serial commands to control a vibrant community of Astromech droid components. Anyone can add their board by editing a JSON library — no code changes required.",
   "license": "MPL-2.0",
   "keywords": [
diff --git a/src/droidnet-command-library.js b/src/droidnet-command-library.js
index a583b48..126ec65 100644
--- a/src/droidnet-command-library.js
+++ b/src/droidnet-command-library.js
@@ -230,7 +230,9 @@
           .sort((a, b) => b.length - a.length); // longest-first so multi-char codes win
         return '(' + codes.join('|') + ')';
       }
-      return '(\\d+)';
+      // Allow an optional leading '-' so int params with a negative range
+      // (e.g. a rotary speed of -80) re-parse to a structured step, not a raw one.
+      return '(-?\\d+)';
     });
     return { re: new RegExp('^' + pattern + '$'), groups };
   }
diff --git a/test/web.test.js b/test/web.test.js
index 02c624d..372886f 100644
--- a/test/web.test.js
+++ b/test/web.test.js
@@ -64,3 +64,27 @@ describe('hosted site — reference data contract', () => {
     expect(bad).toEqual([]);
   });
 });
+
+describe('engine — negative-range int params round-trip (regression)', () => {
+  let cb;
+  beforeEach(() => {
+    cb = loadEngine();
+    const { manifest, boards } = readCatalog();
+    cb.loadLibrary(boards.map(b => JSON.parse(JSON.stringify(b))), { libraryVersion: manifest.libraryVersion });
+  });
+
+  // A non-enum int param whose range allows negatives (uppity.rotary.spin min -100,
+  // uppity.rotary.rel min -180). The matcher must accept a leading '-' so a pasted /
+  // reloaded value re-parses to a structured, editable step instead of a raw step.
+  test("match() accepts a leading '-' for int params", () => {
+    const spin = cb.match(':PR-80');
+    expect(spin).toBeTruthy();
+    expect(spin.commandId).toBe('uppity.rotary.spin');
+    expect(spin.params.speed).toBe('-80');
+
+    const rel = cb.match(':PD-90');
+    expect(rel).toBeTruthy();
+    expect(rel.commandId).toBe('uppity.rotary.rel');
+    expect(rel.params.degrees).toBe('-90');
+  });
+});