diff --git a/more/registrar/registrar.js b/more/registrar/registrar.js
index ed8db841fd6..2785c9bb6b3 100644
--- a/more/registrar/registrar.js
+++ b/more/registrar/registrar.js
@@ -24,12 +24,16 @@ function makeRegistrar(systemVersion, seed = 0) {
       const useCount = (useCounts.get(realName) || 0) + 1;
       useCounts.set(realName, useCount);
       const depth = Math.max(4, Math.floor(Math.log10(useCount) + 1.6));
-      const uniqueString = sparseInts.next().value.toString();
-      const keyString = uniqueString.slice(-depth).padStart(depth, '0');
-      // console.log(`RAND ${useCount} ${uniqueString} ${keyString}`);
-      const key = `${realName}_${keyString}`;
-      // if it was a random keyString, then we need to detect collision
-      insist(!contents.has(key), 'Generated name must not collide');
+
+      // Retry until we have a unique key.
+      let key;
+      do {
+        const uniqueString = sparseInts.next().value.toString();
+        const keyString = uniqueString.slice(-depth).padStart(depth, '0');
+        // console.log(`RAND ${useCount} ${uniqueString} ${keyString}`);
+        key = `${realName}_${keyString}`;
+      } while (contents.has(key));
+
       contents.set(key, value);
       return key;
     },
diff --git a/test/unitTests/more/registrar/test-registrar.js b/test/unitTests/more/registrar/test-registrar.js
new file mode 100644
index 00000000000..4072beb51ee
--- /dev/null
+++ b/test/unitTests/more/registrar/test-registrar.js
@@ -0,0 +1,32 @@
+import { test } from 'tape-promise/tape';
+import { makeRegistrar } from '../../../../more/registrar/registrar';
+
+test('Registrar creation', async t => {
+  try {
+    const registrarService = makeRegistrar('testnet');
+    const obj1 = {};
+    const obj2 = {};
+    const id1 = registrarService.register('myname', obj1);
+    t.assert(id1.match(/^myname_\d{4,}$/), 'id1 is correct format')
+    const id2 = registrarService.register('myname', obj2);
+    t.assert(id2.match(/^myname_\d{4,}$/), 'id2 is correct format')
+    t.isNot(id2, id1, 'ids for different objects are different');
+    const id1a = registrarService.register('myname', obj1);
+    t.assert(id1a.match(/^myname_\d{4,}$/), 'id1a is correct format')
+    t.isNot(id1a, id1, 'ids for same object are different');
+    const id1b = registrarService.register('othername', obj1);
+    t.assert(id1b.match(/^othername_\d{4,}$/), 'id1b is correct format')
+    const ret1 = registrarService.get(id1);
+    t.equals(ret1, obj1, 'returned obj1 is equal');
+    const ret2 = registrarService.get(id2);
+    t.equals(ret2, obj2, 'returned obj2 is equal');
+    const ret1a = registrarService.get(id1a);
+    t.equals(ret1a, obj1, 'returned obj1a is equal');
+    const ret1b = registrarService.get(id1b);
+    t.equals(ret1b, obj1, 'returned obj1b is equal');
+  } catch (e) {
+    t.isNot(e, e, 'unexpected exception');
+  } finally {
+    t.end();
+  }
+});