diff --git a/src/main/java/org/gitlab4j/api/GitLabApi.java b/src/main/java/org/gitlab4j/api/GitLabApi.java
index 772759f06..d2f9274a2 100644
--- a/src/main/java/org/gitlab4j/api/GitLabApi.java
+++ b/src/main/java/org/gitlab4j/api/GitLabApi.java
@@ -96,6 +96,7 @@ public String getApiNamespace() {
     private TodosApi todosApi;
     private UserApi userApi;
     private WikisApi wikisApi;
+    private KeysApi keysApi;
 
     /**
      * Get the GitLab4J shared Logger instance.
@@ -1683,6 +1684,21 @@ public WikisApi getWikisApi() {
         return wikisApi;
     }
 
+    /**
+     * Gets the KeysApi instance owned by this GitLabApi instance. The KeysApi is used to look up users by their ssh key signatures
+     *
+     * @return the KeysApi instance owned by this GitLabApi instance
+     */
+    public KeysApi getKeysAPI() {
+        synchronized (this) {
+            if (keysApi == null) {
+                keysApi = new KeysApi(this);
+            }
+        }
+        return keysApi;
+    }
+
+
     /**
      * Create and return an Optional instance associated with a GitLabApiException.
      *
diff --git a/src/main/java/org/gitlab4j/api/KeysApi.java b/src/main/java/org/gitlab4j/api/KeysApi.java
new file mode 100644
index 000000000..29265ff81
--- /dev/null
+++ b/src/main/java/org/gitlab4j/api/KeysApi.java
@@ -0,0 +1,30 @@
+package org.gitlab4j.api;
+
+import org.gitlab4j.api.models.Key;
+
+import javax.ws.rs.core.MultivaluedHashMap;
+import javax.ws.rs.core.MultivaluedMap;
+import javax.ws.rs.core.Response;
+import java.util.Collections;
+
+/**
+ * See:
+ * https://docs.gitlab.com/ee/api/keys.html#get-user-by-fingerprint-of-ssh-key
+ */
+public class KeysApi extends AbstractApi {
+    public KeysApi(GitLabApi gitLabApi) {
+        super(gitLabApi);
+    }
+
+    /**
+     * @param fingerprint The md5 hash of a ssh public key with : separating the bytes Or SHA256:$base64hash
+     * @return The Key which includes the user who owns the key
+     * @throws GitLabApiException If anything goes wrong
+     */
+    public Key getUserBySSHKeyFingerprint(String fingerprint) throws GitLabApiException {
+        MultivaluedMap<String, String> queryParams = new MultivaluedHashMap<>();
+        queryParams.put("fingerprint", Collections.singletonList(fingerprint));
+        Response response = get(Response.Status.OK, queryParams, "keys");
+        return response.readEntity(Key.class);
+    }
+}
diff --git a/src/main/java/org/gitlab4j/api/UserApi.java b/src/main/java/org/gitlab4j/api/UserApi.java
index 8643dbda1..a8c9b59fe 100644
--- a/src/main/java/org/gitlab4j/api/UserApi.java
+++ b/src/main/java/org/gitlab4j/api/UserApi.java
@@ -5,6 +5,7 @@
 import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
+import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
 import javax.ws.rs.core.Form;
@@ -1306,9 +1307,24 @@ public void deleteGpgKey(final Integer userId, final Integer keyId) throws GitLa
      * @throws GitLabApiException if any exception occurs
      * @since GitLab 12.8
      */
-    public List<Membership> getMemberships(Integer userId) throws GitLabApiException {
+    public List<Membership> getMemberships(int userId) throws GitLabApiException {
+        return getMembershipsPager(userId).stream().collect(Collectors.toList());
+    }
+
+    /**
+     * Returns a Pager that lists all projects and groups a user is a member of. (admin only)
+     *
+     * This allows lazy-fetching of huge numbers of memberships.
+     *
+     * <pre><code>GitLab Endpoint: GET /users/:id/memberships</code></pre>
+     *
+     * @param userId the ID of the user to get the memberships for
+     * @return the list of memberships of the given user
+     * @throws GitLabApiException if any exception occurs
+     * @since GitLab 12.8
+     */
+    public Pager<Membership> getMembershipsPager(int userId) throws GitLabApiException {
         GitLabApiForm formData = new GitLabApiForm();
-        Response response = get(Response.Status.OK, formData.asMap(), "users", userId, "memberships");
-        return (response.readEntity(new GenericType<List<Membership>>() {}));
+        return (new Pager<>(this, Membership.class, 100, formData.asMap(), "users", userId, "memberships"));
     }
 }
diff --git a/src/main/java/org/gitlab4j/api/models/MembershipSourceType.java b/src/main/java/org/gitlab4j/api/models/MembershipSourceType.java
index 8f651f29d..e35dbb4f2 100644
--- a/src/main/java/org/gitlab4j/api/models/MembershipSourceType.java
+++ b/src/main/java/org/gitlab4j/api/models/MembershipSourceType.java
@@ -1,31 +1,38 @@
 package org.gitlab4j.api.models;
 
-import org.gitlab4j.api.utils.JacksonJsonEnumHelper;
-
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonValue;
 
-public enum MembershipSourceType {
+import java.util.Locale;
 
-    PROJECT,
+public enum MembershipSourceType {
+    PROJECT("Project"),
 
     /** Representing a group */
-    NAMESPACE;
+    NAMESPACE("Namespace");
 
-    private static JacksonJsonEnumHelper<MembershipSourceType> enumHelper = new JacksonJsonEnumHelper<>(MembershipSourceType.class);
+    public final String name;
+
+    MembershipSourceType(String name) {
+        this.name = name;
+    }
 
     @JsonCreator
     public static MembershipSourceType forValue(String value) {
-        return enumHelper.forValue(value);
+        if (value == null) {
+            return null;
+        } else {
+            return MembershipSourceType.valueOf(value.toUpperCase(Locale.ROOT));
+        }
     }
 
     @JsonValue
     public String toValue() {
-        return (enumHelper.toString(this));
+        return this.name;
     }
 
     @Override
     public String toString() {
-        return (enumHelper.toString(this));
+        return this.name;
     }
 }
diff --git a/src/test/java/org/gitlab4j/api/models/MembershipSourceTypeTest.java b/src/test/java/org/gitlab4j/api/models/MembershipSourceTypeTest.java
new file mode 100644
index 000000000..f6cc54c70
--- /dev/null
+++ b/src/test/java/org/gitlab4j/api/models/MembershipSourceTypeTest.java
@@ -0,0 +1,19 @@
+package org.gitlab4j.api.models;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+public class MembershipSourceTypeTest {
+
+    @Test
+    public void forValue() {
+        final MembershipSourceType namespace = MembershipSourceType.forValue(MembershipSourceType.NAMESPACE.name);
+        Assert.assertEquals(MembershipSourceType.NAMESPACE, namespace);
+        Assert.assertEquals("Namespace", namespace.name);
+        final MembershipSourceType project = MembershipSourceType.forValue(MembershipSourceType.PROJECT.name);
+        Assert.assertEquals(MembershipSourceType.PROJECT, project);
+        Assert.assertEquals("Project", project.name);
+    }
+}