diff --git a/gerrit-server/src/main/java/com/google/gerrit/rules/StoredValues.java b/gerrit-server/src/main/java/com/google/gerrit/rules/StoredValues.java
index 63a898b86c..b9f476b3d1 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/rules/StoredValues.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/rules/StoredValues.java
@@ -16,12 +16,16 @@ package com.google.gerrit.rules;
 
 import static com.google.gerrit.rules.StoredValue.create;
 
+import com.google.common.collect.Maps;
+import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.reviewdb.client.AccountDiffPreference.Whitespace;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.PatchSet;
 import com.google.gerrit.reviewdb.client.PatchSetInfo;
 import com.google.gerrit.reviewdb.client.Project;
-import com.google.gerrit.reviewdb.client.AccountDiffPreference.Whitespace;
 import com.google.gerrit.reviewdb.server.ReviewDb;
+import com.google.gerrit.server.AnonymousUser;
+import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.gerrit.server.patch.PatchList;
 import com.google.gerrit.server.patch.PatchListCache;
@@ -38,6 +42,8 @@ import org.eclipse.jgit.errors.RepositoryNotFoundException;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.Repository;
 
+import java.util.Map;
+
 public final class StoredValues {
   public static final StoredValue<ReviewDb> REVIEW_DB = create(ReviewDb.class);
   public static final StoredValue<Change> CHANGE = create(Change.class);
@@ -105,6 +111,23 @@ public final class StoredValues {
     }
   };
 
+  public static final StoredValue<AnonymousUser> ANONYMOUS_USER =
+      new StoredValue<AnonymousUser>() {
+        @Override
+        protected AnonymousUser createValue(Prolog engine) {
+          PrologEnvironment env = (PrologEnvironment) engine.control;
+          return env.getInjector().getInstance(AnonymousUser.class);
+        }
+      };
+
+  public static final StoredValue<Map<Account.Id, IdentifiedUser>> USERS =
+      new StoredValue<Map<Account.Id, IdentifiedUser>>() {
+        @Override
+        protected Map<Account.Id, IdentifiedUser> createValue(Prolog engine) {
+          return Maps.newHashMap();
+        }
+      };
+
   private StoredValues() {
   }
 }
\ No newline at end of file
diff --git a/gerrit-server/src/main/java/gerrit/PRED_current_user_2.java b/gerrit-server/src/main/java/gerrit/PRED_current_user_2.java
index 9005180804..1359de1088 100644
--- a/gerrit-server/src/main/java/gerrit/PRED_current_user_2.java
+++ b/gerrit-server/src/main/java/gerrit/PRED_current_user_2.java
@@ -20,16 +20,12 @@ import com.google.gerrit.reviewdb.client.Account;
 import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.rules.PrologEnvironment;
 import com.google.gerrit.rules.StoredValues;
-import com.google.gerrit.server.AnonymousUser;
 import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.IdentifiedUser;
-import com.google.inject.Provider;
 import com.google.inject.util.Providers;
 
-import com.googlecode.prolog_cafe.lang.HashtableOfTerm;
 import com.googlecode.prolog_cafe.lang.IllegalTypeException;
 import com.googlecode.prolog_cafe.lang.IntegerTerm;
-import com.googlecode.prolog_cafe.lang.InternalException;
 import com.googlecode.prolog_cafe.lang.JavaObjectTerm;
 import com.googlecode.prolog_cafe.lang.Operation;
 import com.googlecode.prolog_cafe.lang.PInstantiationException;
@@ -40,6 +36,8 @@ import com.googlecode.prolog_cafe.lang.StructureTerm;
 import com.googlecode.prolog_cafe.lang.SymbolTerm;
 import com.googlecode.prolog_cafe.lang.Term;
 
+import java.util.Map;
+
 /**
  * Loads a CurrentUser object for a user identity.
  * <p>
@@ -54,7 +52,6 @@ class PRED_current_user_2 extends Predicate.P2 {
   private static final long serialVersionUID = 1L;
   private static final SymbolTerm user = intern("user", 1);
   private static final SymbolTerm anonymous = intern("anonymous");
-  private static final SymbolTerm current_user = intern("current_user");
 
   PRED_current_user_2(Term a1, Term a2, Operation n) {
     arg1 = a1;
@@ -72,24 +69,14 @@ class PRED_current_user_2 extends Predicate.P2 {
       throw new PInstantiationException(this, 1);
     }
 
-    HashtableOfTerm userHash = userHash(engine);
-    Term userTerm = userHash.get(a1);
-    if (userTerm != null && userTerm.isJavaObject()) {
-      if (!(((JavaObjectTerm) userTerm).object() instanceof CurrentUser)) {
-        userTerm = createUser(engine, a1, userHash);
-      }
-    } else {
-      userTerm = createUser(engine, a1, userHash);
-    }
-
-    if (!a2.unify(userTerm, engine.trail)) {
+    if (!a2.unify(createUser(engine, a1), engine.trail)) {
       return engine.fail();
     }
 
     return cont;
   }
 
-  public Term createUser(Prolog engine, Term key, HashtableOfTerm userHash) {
+  public Term createUser(Prolog engine, Term key) {
     if (!key.isStructure()
         || key.arity() != 1
         || !((StructureTerm) key).functor().equals(user)) {
@@ -99,50 +86,30 @@ class PRED_current_user_2 extends Predicate.P2 {
     Term idTerm = key.arg(0);
     CurrentUser user;
     if (idTerm.isInteger()) {
+      Map<Account.Id, IdentifiedUser> cache = StoredValues.USERS.get(engine);
       Account.Id accountId = new Account.Id(((IntegerTerm) idTerm).intValue());
-
-      final ReviewDb db = StoredValues.REVIEW_DB.getOrNull(engine);
-      IdentifiedUser.GenericFactory userFactory = userFactory(engine);
-      if (db != null) {
-        user = userFactory.create(Providers.of(db), accountId);
-      } else {
-        user = userFactory.create(accountId);
+      user = cache.get(accountId);
+      if (user == null) {
+        ReviewDb db = StoredValues.REVIEW_DB.getOrNull(engine);
+        IdentifiedUser.GenericFactory userFactory = userFactory(engine);
+        IdentifiedUser who;
+        if (db != null) {
+          who = userFactory.create(Providers.of(db), accountId);
+        } else {
+          who = userFactory.create(accountId);
+        }
+        cache.put(accountId, who);
+        user = who;
       }
 
-
     } else if (idTerm.equals(anonymous)) {
-      user = anonymousUser(engine);
+      user = StoredValues.ANONYMOUS_USER.get(engine);
 
     } else {
       throw new IllegalTypeException(this, 1, "user(int)", key);
     }
 
-    Term userTerm = new JavaObjectTerm(user);
-    userHash.put(key, userTerm);
-    return userTerm;
-  }
-
-  private static HashtableOfTerm userHash(Prolog engine) {
-    Term userHash = engine.getHashManager().get(current_user);
-    if (userHash == null) {
-      HashtableOfTerm users = new HashtableOfTerm();
-      engine.getHashManager().put(current_user, new JavaObjectTerm(userHash));
-      return users;
-    }
-
-    if (userHash.isJavaObject()) {
-      Object obj = ((JavaObjectTerm) userHash).object();
-      if (obj instanceof HashtableOfTerm) {
-        return (HashtableOfTerm) obj;
-      }
-    }
-
-    throw new InternalException(current_user + " is not HashtableOfTerm");
-  }
-
-  private static AnonymousUser anonymousUser(Prolog engine) {
-    PrologEnvironment env = (PrologEnvironment) engine.control;
-    return env.getInjector().getInstance(AnonymousUser.class);
+    return new JavaObjectTerm(user);
   }
 
   private static IdentifiedUser.GenericFactory userFactory(Prolog engine) {