diff --git a/java/com/google/gerrit/plugins/codeowners/backend/CodeOwnerResolver.java b/java/com/google/gerrit/plugins/codeowners/backend/CodeOwnerResolver.java
index 6ed577e..254b3a6 100644
--- a/java/com/google/gerrit/plugins/codeowners/backend/CodeOwnerResolver.java
+++ b/java/com/google/gerrit/plugins/codeowners/backend/CodeOwnerResolver.java
@@ -47,6 +47,8 @@
 import java.io.IOException;
 import java.nio.file.Path;
 import java.util.Collection;
+import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
@@ -439,6 +441,8 @@
       hasUnresolvedCodeOwners.set(true);
     }
 
+    Map<CodeOwner, Set<CodeOwnerAnnotation>> codeOwnersWithAnnotations = new HashMap<>();
+
     // Merge code owners that have been newly resolved with code owners which have been looked up
     // from cache and return them with their annotations.
     Stream<Pair<String, CodeOwner>> newlyResolvedCodeOwnersStream =
@@ -447,22 +451,25 @@
         cachedCodeOwnersByEmail.entrySet().stream()
             .filter(e -> e.getValue().isPresent())
             .map(e -> Pair.of(e.getKey(), e.getValue().get()));
-    return Streams.concat(newlyResolvedCodeOwnersStream, cachedCodeOwnersStream)
-        .collect(
-            toImmutableMap(
-                Pair::value,
-                p -> {
-                  ImmutableSet.Builder<CodeOwnerAnnotation> annotationBuilder =
-                      ImmutableSet.builder();
+    Streams.concat(newlyResolvedCodeOwnersStream, cachedCodeOwnersStream)
+        .forEach(
+            p -> {
+              ImmutableSet.Builder<CodeOwnerAnnotation> annotationBuilder = ImmutableSet.builder();
 
-                  annotationBuilder.addAll(annotations.get(CodeOwnerReference.create(p.key())));
+              annotationBuilder.addAll(annotations.get(CodeOwnerReference.create(p.key())));
 
-                  // annotations for the all users wildcard (aka '*') apply to all code owners
-                  annotationBuilder.addAll(
-                      annotations.get(CodeOwnerReference.create(ALL_USERS_WILDCARD)));
+              // annotations for the all users wildcard (aka '*') apply to all code owners
+              annotationBuilder.addAll(
+                  annotations.get(CodeOwnerReference.create(ALL_USERS_WILDCARD)));
 
-                  return annotationBuilder.build();
-                }));
+              if (!codeOwnersWithAnnotations.containsKey(p.value())) {
+                codeOwnersWithAnnotations.put(p.value(), new HashSet<>());
+              }
+              codeOwnersWithAnnotations.get(p.value()).addAll(annotationBuilder.build());
+            });
+
+    return codeOwnersWithAnnotations.entrySet().stream()
+        .collect(toImmutableMap(Map.Entry::getKey, e -> ImmutableSet.copyOf(e.getValue())));
   }
 
   /**
diff --git a/javatests/com/google/gerrit/plugins/codeowners/backend/CodeOwnerResolverTest.java b/javatests/com/google/gerrit/plugins/codeowners/backend/CodeOwnerResolverTest.java
index 6c6df4f..06e5ab1 100644
--- a/javatests/com/google/gerrit/plugins/codeowners/backend/CodeOwnerResolverTest.java
+++ b/javatests/com/google/gerrit/plugins/codeowners/backend/CodeOwnerResolverTest.java
@@ -485,6 +485,36 @@
   }
 
   @Test
+  public void resolvePathCodeOwnersWithAnnotations_annotationOnMultipleEmailsOfTheSameUser()
+      throws Exception {
+    // add secondary email to user account
+    String secondaryEmail = "user@foo.bar";
+    accountOperations.account(user.id()).forUpdate().addSecondaryEmail(secondaryEmail).update();
+
+    CodeOwnerConfig codeOwnerConfig =
+        CodeOwnerConfig.builder(CodeOwnerConfig.Key.create(project, "master", "/"), TEST_REVISION)
+            .addCodeOwnerSet(
+                CodeOwnerSet.builder()
+                    .addCodeOwnerEmail(user.email())
+                    .addAnnotation(user.email(), CodeOwnerAnnotation.create("FOO"))
+                    .addCodeOwnerEmail(secondaryEmail)
+                    .addAnnotation(secondaryEmail, CodeOwnerAnnotation.create("BAR"))
+                    .build())
+            .build();
+
+    // admin has the "Modify Account" global capability and hence can see the secondary email of the
+    // user account.
+    CodeOwnerResolverResult result =
+        codeOwnerResolverProvider
+            .get()
+            .resolvePathCodeOwners(codeOwnerConfig, Paths.get("/README.md"));
+    assertThat(result.codeOwnersAccountIds()).containsExactly(user.id());
+    assertThat(result.annotations().keySet()).containsExactly(CodeOwner.create(user.id()));
+    assertThat(result.annotations().get(CodeOwner.create(user.id())))
+        .containsExactly(CodeOwnerAnnotation.create("FOO"), CodeOwnerAnnotation.create("BAR"));
+  }
+
+  @Test
   public void cannotResolvePathCodeOwnersOfNullCodeOwnerConfig() throws Exception {
     NullPointerException npe =
         assertThrows(
@@ -738,4 +768,24 @@
     assertThat(testMetricMaker.getCount("plugins/code-owners/count_code_owner_cache_reads"))
         .isEqualTo(1);
   }
+
+  @Test
+  public void resolveCodeOwnerReferencesThatPointToTheSameAccount() throws Exception {
+    // add secondary email to user account
+    String secondaryEmail = "user@foo.bar";
+    accountOperations.account(user.id()).forUpdate().addSecondaryEmail(secondaryEmail).update();
+
+    // admin has the "Modify Account" global capability and hence can see the secondary email of the
+    // user account.
+    CodeOwnerResolverResult result =
+        codeOwnerResolverProvider
+            .get()
+            .resolve(
+                ImmutableSet.of(
+                    CodeOwnerReference.create(user.email()),
+                    CodeOwnerReference.create(secondaryEmail)));
+    assertThat(result.codeOwnersAccountIds()).containsExactly(user.id());
+    assertThat(result.ownedByAllUsers()).isFalse();
+    assertThat(result.hasUnresolvedCodeOwners()).isFalse();
+  }
 }