diff --git a/pc/peer_connection.cc b/pc/peer_connection.cc
index f318acf4ff..88b99bb515 100644
--- a/pc/peer_connection.cc
+++ b/pc/peer_connection.cc
@@ -1092,7 +1092,7 @@ PeerConnection::AddTransceiver(
   if (parameters.encodings.size() > 1 && num_rids == 0) {
     rtc::UniqueStringGenerator rid_generator;
     for (RtpEncodingParameters& encoding : parameters.encodings) {
-      encoding.rid = rid_generator();
+      encoding.rid = rid_generator.GenerateString();
     }
   }
 
diff --git a/pc/peer_connection_simulcast_unittest.cc b/pc/peer_connection_simulcast_unittest.cc
index 54b49309bb..98179f9829 100644
--- a/pc/peer_connection_simulcast_unittest.cc
+++ b/pc/peer_connection_simulcast_unittest.cc
@@ -117,7 +117,7 @@ std::vector<SimulcastLayer> CreateLayers(int num_layers, bool active) {
   rtc::UniqueStringGenerator rid_generator;
   std::vector<std::string> rids;
   for (int i = 0; i < num_layers; ++i) {
-    rids.push_back(rid_generator());
+    rids.push_back(rid_generator.GenerateString());
   }
   return CreateLayers(rids, active);
 }
diff --git a/rtc_base/unique_id_generator.h b/rtc_base/unique_id_generator.h
index 342dad7766..d103caf2fc 100644
--- a/rtc_base/unique_id_generator.h
+++ b/rtc_base/unique_id_generator.h
@@ -44,7 +44,9 @@ class UniqueNumberGenerator {
   // If there are no available numbers to generate, this method will fail
   // with an `RTC_CHECK`.
   TIntegral GenerateNumber();
-  TIntegral operator()() { return GenerateNumber(); }
+
+  // Alias for GenerateId, used for allowing typed testing
+  TIntegral Generate() { return GenerateNumber(); }
 
   // Adds an id that this generator should no longer generate.
   // Return value indicates whether the ID was hitherto unknown.
@@ -74,7 +76,9 @@ class UniqueRandomIdGenerator {
   // This method becomes more expensive with each use, as the probability of
   // collision for the randomly generated numbers increases.
   uint32_t GenerateId();
-  uint32_t operator()() { return GenerateId(); }
+
+  // Alias for GenerateId, used for allowing typed testing
+  uint32_t Generate() { return GenerateId(); }
 
   // Adds an id that this generator should no longer generate.
   // Return value indicates whether the ID was hitherto unknown.
@@ -100,7 +104,8 @@ class UniqueStringGenerator {
   ~UniqueStringGenerator();
 
   std::string GenerateString();
-  std::string operator()() { return GenerateString(); }
+  // Alias for GenerateString, used for allowing typed testing
+  std::string Generate() { return GenerateString(); }
 
   // Adds an id that this generator should no longer generate.
   // Return value indicates whether the ID was hitherto unknown.
diff --git a/rtc_base/unique_id_generator_unittest.cc b/rtc_base/unique_id_generator_unittest.cc
index c6eb511e57..ec9c3fb4e5 100644
--- a/rtc_base/unique_id_generator_unittest.cc
+++ b/rtc_base/unique_id_generator_unittest.cc
@@ -62,7 +62,7 @@ TYPED_TEST(UniqueIdGeneratorTest, ElementsDoNotRepeat) {
   Generator generator;
   std::vector<typename Generator::value_type> values;
   for (size_t i = 0; i < num_elements; i++) {
-    values.push_back(generator());
+    values.push_back(generator.Generate());
   }
 
   EXPECT_EQ(num_elements, values.size());
@@ -78,7 +78,7 @@ TYPED_TEST(UniqueIdGeneratorTest, KnownElementsAreNotGenerated) {
   Generator generator1;
   std::vector<typename Generator::value_type> known_values;
   for (size_t i = 0; i < num_elements; i++) {
-    known_values.push_back(generator1());
+    known_values.push_back(generator1.Generate());
   }
   EXPECT_EQ(num_elements, known_values.size());
 
@@ -87,7 +87,7 @@ TYPED_TEST(UniqueIdGeneratorTest, KnownElementsAreNotGenerated) {
 
   std::vector<typename Generator::value_type> values;
   for (size_t i = 0; i < num_elements; i++) {
-    values.push_back(generator2());
+    values.push_back(generator2.Generate());
   }
   EXPECT_THAT(values, ::testing::SizeIs(num_elements));
   absl::c_sort(values);
@@ -105,7 +105,7 @@ TYPED_TEST(UniqueIdGeneratorTest, AddedElementsAreNotGenerated) {
   Generator generator1;
   std::vector<typename Generator::value_type> known_values;
   for (size_t i = 0; i < num_elements; i++) {
-    known_values.push_back(generator1());
+    known_values.push_back(generator1.Generate());
   }
   EXPECT_EQ(num_elements, known_values.size());
 
@@ -118,7 +118,7 @@ TYPED_TEST(UniqueIdGeneratorTest, AddedElementsAreNotGenerated) {
 
   std::vector<typename Generator::value_type> values;
   for (size_t i = 0; i < num_elements; i++) {
-    values.push_back(generator2());
+    values.push_back(generator2.Generate());
   }
   EXPECT_THAT(values, ::testing::SizeIs(num_elements));
   absl::c_sort(values);
@@ -134,7 +134,7 @@ TYPED_TEST(UniqueIdGeneratorTest, AddKnownIdOnNewIdReturnsTrue) {
 
   rtc::InitRandom(0);
   Generator generator1;
-  const typename Generator::value_type id = generator1();
+  const typename Generator::value_type id = generator1.Generate();
 
   rtc::InitRandom(0);
   Generator generator2;
@@ -146,7 +146,7 @@ TYPED_TEST(UniqueIdGeneratorTest, AddKnownIdCalledAgainForSameIdReturnsFalse) {
 
   rtc::InitRandom(0);
   Generator generator1;
-  const typename Generator::value_type id = generator1();
+  const typename Generator::value_type id = generator1.Generate();
 
   rtc::InitRandom(0);
   Generator generator2;
@@ -160,7 +160,7 @@ TYPED_TEST(UniqueIdGeneratorTest,
 
   rtc::InitRandom(0);
   Generator generator1;
-  const typename Generator::value_type id = generator1();
+  const typename Generator::value_type id = generator1.Generate();
   std::vector<typename Generator::value_type> known_values = {id};
 
   rtc::InitRandom(0);
@@ -182,7 +182,7 @@ TEST(UniqueNumberGenerator, UsedOnSecondaryThread) {
   ASSERT_NE(current_tq, webrtc::TaskQueueBase::Current());
 
   // Generating an id should be fine in this context.
-  generator.GenerateNumber();
+  generator.Generate();
 }
 
 #if RTC_DCHECK_IS_ON && GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
@@ -196,13 +196,13 @@ TEST(UniqueNumberGeneratorDeathTest, FailsWhenUsedInWrongContext) {
   FakeTaskQueue initial_fake_task_queue;
   // Generate an ID on the current thread. This causes the generator to attach
   // to the current thread context.
-  generator.GenerateNumber();
+  generator.Generate();
 
   // Instantiate a fake task queue that will register itself as the current tq.
   FakeTaskQueue fake_task_queue;
 
   // Attempting to generate an id should now trigger a dcheck.
-  EXPECT_DEATH(generator.GenerateNumber(), "");
+  EXPECT_DEATH(generator.Generate(), "");
 }
 #endif
 
diff --git a/video/video_send_stream_tests.cc b/video/video_send_stream_tests.cc
index 7b33ca2fde..038ae80792 100644
--- a/video/video_send_stream_tests.cc
+++ b/video/video_send_stream_tests.cc
@@ -3786,7 +3786,8 @@ class PacingFactorObserver : public test::SendTest {
       }
       // Want send side, not present by default, so add it.
       send_config->rtp.extensions.emplace_back(
-          RtpExtension::kTransportSequenceNumberUri, unique_id_generator());
+          RtpExtension::kTransportSequenceNumberUri,
+          unique_id_generator.GenerateNumber());
     }
 
     // ALR only enabled for screenshare.