diff --git a/chrome/browser/ash/input_method/assistive_suggester_unittest.cc b/chrome/browser/ash/input_method/assistive_suggester_unittest.cc
index 6279963e15f36..76c3c6ef5a6ab 100644
--- a/chrome/browser/ash/input_method/assistive_suggester_unittest.cc
+++ b/chrome/browser/ash/input_method/assistive_suggester_unittest.cc
@@ -472,6 +472,25 @@ TEST_F(AssistiveSuggesterTest,
   EXPECT_EQ(suggestion_handler_->GetSuggestionText(), u"à;á;â;ã;ã;ä;å;ā");
 }
 
+TEST_F(AssistiveSuggesterTest, DiacriticsSuggestionOnKeyDownRecordsSuccess) {
+  base::test::ScopedFeatureList feature_list;
+  feature_list.InitWithFeatures(
+      /*enabled_features=*/{features::kDiacriticsOnPhysicalKeyboardLongpress},
+      /*disabled_features=*/{});
+  SetInputMethodOptions(*profile_, /*predictive_writing_enabled=*/false,
+                        /*diacritics_on_longpress_enabled=*/true);
+  assistive_suggester_->OnActivate(kUsEnglishEngineId);
+  assistive_suggester_->OnFocus(5);
+
+  EXPECT_FALSE(assistive_suggester_->OnKeyEvent(PressKey(ui::DomCode::US_A)));
+  task_environment_.FastForwardBy(base::Seconds(1));
+  EXPECT_TRUE(assistive_suggester_->OnKeyEvent(PressKey(ui::DomCode::DIGIT1)));
+
+  histogram_tester_.ExpectTotalCount("InputMethod.Assistive.Success", 1);
+  histogram_tester_.ExpectUniqueSample("InputMethod.Assistive.Success",
+                                       AssistiveType::kLongpressDiacritics, 1);
+}
+
 TEST_F(AssistiveSuggesterTest,
        NoDiacriticsSuggestionOnKeyDownLongpressForUSEnglishOnPrefDisabled) {
   base::test::ScopedFeatureList feature_list;
diff --git a/chrome/browser/ash/input_method/longpress_diacritics_suggester.cc b/chrome/browser/ash/input_method/longpress_diacritics_suggester.cc
index 83c05c7162c24..31ddd42d26019 100644
--- a/chrome/browser/ash/input_method/longpress_diacritics_suggester.cc
+++ b/chrome/browser/ash/input_method/longpress_diacritics_suggester.cc
@@ -230,8 +230,7 @@ void LongpressDiacriticsSuggester::DismissSuggestion() {
 }
 
 AssistiveType LongpressDiacriticsSuggester::GetProposeActionType() {
-  // TODO(b/217560706): Should handle action.
-  return AssistiveType::kGenericAction;
+  return AssistiveType::kLongpressDiacritics;
 }
 
 bool LongpressDiacriticsSuggester::HasSuggestions() {
diff --git a/chrome/browser/ash/input_method/longpress_diacritics_suggester_unittest.cc b/chrome/browser/ash/input_method/longpress_diacritics_suggester_unittest.cc
index cea0d65e05d08..57117b52a026c 100644
--- a/chrome/browser/ash/input_method/longpress_diacritics_suggester_unittest.cc
+++ b/chrome/browser/ash/input_method/longpress_diacritics_suggester_unittest.cc
@@ -9,6 +9,7 @@
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "chrome/browser/ash/input_method/fake_suggestion_handler.h"
+#include "chrome/browser/ash/input_method/suggestion_enums.h"
 #include "chrome/test/base/testing_profile.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/events/base_event_utils.h"
@@ -612,6 +613,16 @@ TEST_P(LongpressDiacriticsSuggesterTest, NoDismissSuggestionOnRepeatKeyPress) {
   EXPECT_FALSE(suggestion_handler.GetAcceptedSuggestion());
 }
 
+TEST_P(LongpressDiacriticsSuggesterTest, ReturnsDiacriticsProposeActionType) {
+  FakeSuggestionHandler suggestion_handler;
+  LongpressDiacriticsSuggester suggester =
+      LongpressDiacriticsSuggester(&suggestion_handler);
+  suggester.OnFocus(kContextId);
+
+  EXPECT_EQ(suggester.GetProposeActionType(),
+            AssistiveType::kLongpressDiacritics);
+}
+
 INSTANTIATE_TEST_SUITE_P(
     /* no prefix */,
     LongpressDiacriticsSuggesterTest,
diff --git a/chrome/browser/ash/input_method/suggestion_enums.h b/chrome/browser/ash/input_method/suggestion_enums.h
index 524d8aa81cc01..3ab2275fe7dca 100644
--- a/chrome/browser/ash/input_method/suggestion_enums.h
+++ b/chrome/browser/ash/input_method/suggestion_enums.h
@@ -25,7 +25,8 @@ enum class AssistiveType {
   kAutocorrectReverted = 12,
   kMultiWordPrediction = 13,
   kMultiWordCompletion = 14,
-  kMaxValue = kMultiWordCompletion,
+  kLongpressDiacritics = 15,
+  kMaxValue = kLongpressDiacritics,
 };
 
 enum class SuggestionStatus {
diff --git a/tools/metrics/histograms/enums.xml b/tools/metrics/histograms/enums.xml
index 1ae29e2a78670..7be88e6d5fff2 100644
--- a/tools/metrics/histograms/enums.xml
+++ b/tools/metrics/histograms/enums.xml
@@ -49782,6 +49782,7 @@ Called by update_gpu_driver_bug_workaround_entries.py.-->
   <int value="12" label="AUTOCORRECT_REVERTED"/>
   <int value="13" label="MULTIWORD_PREDICTION"/>
   <int value="14" label="MULTIWORD_COMPLETION"/>
+  <int value="15" label="LONGPRESS_DIACRITICS"/>
 </enum>
 
 <enum name="IMEAssistiveDisabledReason">