diff --git a/CHANGELOG.md b/CHANGELOG.md
index ade75bf..1b77e17 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+# upcoming
+
+- feature: Support the system's new concentration rolls with sources and messages (system already handles advantage/disadvantage)
+
 # 3.4.1
 
 - feature: [#64](https://github.com/kaelad02/adv-reminder/pull/64) Add pt-BR translation, thanks @Kharmans
diff --git a/src/messages.js b/src/messages.js
index 64df4f0..20b79db 100644
--- a/src/messages.js
+++ b/src/messages.js
@@ -29,10 +29,15 @@ class BaseMessage {
   addMessage(options) {
     debug("checking for message effects");
 
+    // get any existing messages
+    const messages = getProperty(options, "dialogOptions.adv-reminder.messages") ?? [];
+
+    // get messages from the actor and merge
     const keys = this.messageKeys;
-    const messages = this.changes
+    const actorMessages = this.changes
       .filter((change) => keys.includes(change.key))
       .map((change) => change.value);
+    messages.push(...actorMessages);
 
     // get messages from the target and merge
     const targetKeys = this.targetKeys;
@@ -114,6 +119,14 @@ export class AbilitySaveMessage extends AbilityBaseMessage {
   }
 }
 
+export class ConcentrationMessage extends AbilityBaseMessage {
+  /** @override */
+  get messageKeys() {
+    // don't call super since the system will trigger a saving throw
+    return ["flags.adv-reminder.message.ability.concentration"];
+  }
+}
+
 export class SkillMessage extends AbilityCheckMessage {
   constructor(actor, abilityId, skillId) {
     super(actor, abilityId);
diff --git a/src/reminders.js b/src/reminders.js
index ca51e43..2ae2d98 100644
--- a/src/reminders.js
+++ b/src/reminders.js
@@ -22,12 +22,14 @@ class BaseReminder {
 
   /**
    * An accumulator that looks for matching keys and tracks advantage/disadvantage.
+   * @param {Object} options
+   * @param {boolean} options.advantage initial value for advantage
+   * @param {boolean} options.disadvantage initial value for disadvantage
    */
-  _accumulator() {
-    let advantage;
-    let disadvantage;
-
+  _accumulator({advantage, disadvantage} = {}) {
     return {
+      advantage,
+      disadvantage,
       add: (actorFlags, advKeys, disKeys) => {
         advantage = advKeys.reduce((accum, curr) => accum || actorFlags[curr], advantage);
         disadvantage = disKeys.reduce((accum, curr) => accum || actorFlags[curr], disadvantage);
@@ -38,8 +40,16 @@ class BaseReminder {
       update: (options) => {
         debug(`updating options with {advantage: ${advantage}, disadvantage: ${disadvantage}}`);
         // only set if adv or dis, the die roller doesn't handle when both are true correctly
-        if (advantage && !disadvantage) options.advantage = true;
-        else if (!advantage && disadvantage) options.disadvantage = true;
+        if (advantage && !disadvantage) {
+          options.advantage = true;
+          if (options.disadvantage) options.disadvantage = false;
+        } else if (!advantage && disadvantage) {
+          if (options.advantage) options.advantage = false;
+          options.disadvantage = true;
+        } else {
+          if (options.advantage) options.advantage = false;
+          if (options.disadvantage) options.disadvantage = false;
+        }
       },
     };
   }
@@ -121,7 +131,7 @@ class AbilityBaseReminder extends BaseReminder {
     debug("advKeys", advKeys, "disKeys", disKeys);
 
     // find matching keys and update options
-    const accumulator = this._accumulator();
+    const accumulator = options.isConcentration ? this._accumulator(options) : this._accumulator();
     accumulator.add(this.actorFlags, advKeys, disKeys);
     accumulator.update(options);
   }
diff --git a/src/rollers/core.js b/src/rollers/core.js
index 95c5d2a..6981a03 100644
--- a/src/rollers/core.js
+++ b/src/rollers/core.js
@@ -3,6 +3,7 @@ import {
   AbilityCheckMessage,
   AbilitySaveMessage,
   AttackMessage,
+  ConcentrationMessage,
   DamageMessage,
   DeathSaveMessage,
   SkillMessage,
@@ -19,6 +20,7 @@ import {
   AbilityCheckSource,
   AbilitySaveSource,
   AttackSource,
+  ConcentrationSource,
   CriticalSource,
   DeathSaveSource,
   SkillSource,
@@ -47,6 +49,7 @@ export default class CoreRollerHooks {
     // register all the dnd5e.pre hooks
     Hooks.on("dnd5e.preRollAttack", this.preRollAttack.bind(this));
     Hooks.on("dnd5e.preRollAbilitySave", this.preRollAbilitySave.bind(this));
+    Hooks.on("dnd5e.preRollConcentration", this.preRollConcentration.bind(this));
     Hooks.on("dnd5e.preRollAbilityTest", this.preRollAbilityTest.bind(this));
     Hooks.on("dnd5e.preRollSkill", this.preRollSkill.bind(this));
     Hooks.on("dnd5e.preRollToolCheck", this.preRollToolCheck.bind(this));
@@ -86,6 +89,16 @@ export default class CoreRollerHooks {
     new AbilitySaveReminder(actor, abilityId).updateOptions(config);
   }
 
+  preRollConcentration(actor, options) {
+    debug("preRollConcentration hook called");
+
+    if (this.isFastForwarding(options)) return;
+
+    new ConcentrationMessage(actor, options.ability).addMessage(options);
+    if (showSources) new ConcentrationSource(actor, options.ability).updateOptions(options);
+    // don't need a reminder, the system will set advantage/disadvantage
+  }
+
   preRollAbilityTest(actor, config, abilityId) {
     debug("preRollAbilityTest hook called");
 
diff --git a/src/rollers/midi.js b/src/rollers/midi.js
index 33ee16a..5afe23c 100644
--- a/src/rollers/midi.js
+++ b/src/rollers/midi.js
@@ -2,6 +2,7 @@ import {
   AbilityCheckMessage,
   AbilitySaveMessage,
   AttackMessage,
+  ConcentrationMessage,
   DamageMessage,
   DeathSaveMessage,
   SkillMessage,
@@ -10,6 +11,7 @@ import {
   AbilityCheckSource,
   AbilitySaveSource,
   AttackSource,
+  ConcentrationSource,
   CriticalSource,
   DeathSaveSource,
   SkillSource,
@@ -45,6 +47,15 @@ export default class MidiRollerHooks extends CoreRollerHooks {
     if (showSources) new AbilitySaveSource(actor, abilityId).updateOptions(config);
   }
 
+  preRollConcentration(actor, options) {
+    debug("preRollConcentration hook called");
+
+    if (this.isFastForwarding(options)) return;
+
+    new ConcentrationMessage(actor, options.ability).addMessage(options);
+    if (showSources) new ConcentrationSource(actor, options.ability).updateOptions(options);
+  }
+
   preRollAbilityTest(actor, config, abilityId) {
     debug("preRollAbilityTest hook called");
 
diff --git a/src/rollers/rsr.js b/src/rollers/rsr.js
index 69481b3..648340c 100644
--- a/src/rollers/rsr.js
+++ b/src/rollers/rsr.js
@@ -3,6 +3,7 @@ import {
   AbilityCheckMessage,
   AbilitySaveMessage,
   AttackMessage,
+  ConcentrationMessage,
   DamageMessage,
   DeathSaveMessage,
   SkillMessage,
@@ -19,6 +20,7 @@ import {
   AbilityCheckSource,
   AbilitySaveSource,
   AttackSource,
+  ConcentrationSource,
   CriticalSource,
   DeathSaveSource,
   SkillSource,
@@ -69,6 +71,16 @@ export default class ReadySetRollHooks extends CoreRollerHooks {
     if (this._doReminder(config)) new AbilitySaveReminder(actor, abilityId).updateOptions(config);
   }
 
+  preRollConcentration(actor, options) {
+    debug("preRollConcentration hook called");
+
+    if (this._doMessages(options)) {
+      new ConcentrationMessage(actor, options.ability).addMessage(options);
+      if (showSources) new ConcentrationSource(actor, options.ability).updateOptions(options);
+    }
+    // don't need a reminder, the system will set advantage/disadvantage
+  }
+
   preRollAbilityTest(actor, config, abilityId) {
     debug("preRollAbilityTest hook called");
 
diff --git a/src/sources.js b/src/sources.js
index 9c0eca5..8877433 100644
--- a/src/sources.js
+++ b/src/sources.js
@@ -47,6 +47,9 @@ const SourceMixin = (superclass) =>
             if (changes[key]) disadvantageLabels.push(...changes[key]);
           });
         },
+        advantage: (label) => {
+          if (label) advantageLabels.push(label);
+        },
         disadvantage: (label) => {
           if (label) disadvantageLabels.push(label);
         },
@@ -70,6 +73,31 @@ export class AttackSource extends SourceMixin(AttackReminder) {}
 
 export class AbilitySaveSource extends SourceMixin(AbilitySaveReminder) {}
 
+export class ConcentrationSource extends SourceMixin(Object) {
+  constructor(actor, abilityId) {
+    super();
+    
+    /** @type {object} */
+    this.conc = actor.system.attributes?.concentration;
+    /** @type {string} */
+    this.abilityId = abilityId;
+  }
+
+  updateOptions(options) {
+    this._message();
+
+    const modes = CONFIG.Dice.D20Roll.ADV_MODE;
+    const source = () =>
+      game.i18n.localize("DND5E.Concentration") + " " + game.i18n.localize("DND5E.AdvantageMode");
+
+    // check Concentration's roll mode to look for advantage/disadvantage
+    const accumulator = this._accumulator();
+    if (this.conc.roll.mode === modes.ADVANTAGE) accumulator.advantage(source());
+    else if (this.conc.roll.mode === modes.DISADVANTAGE) accumulator.disadvantage(source());
+    accumulator.update(options);
+  }
+}
+
 export class AbilityCheckSource extends SourceMixin(AbilityCheckReminder) {}
 
 export class SkillSource extends SourceMixin(SkillReminder) {}
diff --git a/test/common.js b/test/common.js
index fd820b3..a9aaaf8 100644
--- a/test/common.js
+++ b/test/common.js
@@ -24,6 +24,19 @@ export default function commonTestInit() {
     lastObj[lastProp] = value;
   };
 
+  globalThis.getProperty = (object, key) => {
+    if (!key) return undefined;
+    if (key in object) return object[key];
+    let target = object;
+    for (let p of key.split(".")) {
+      getType(target);
+      if (!(typeof target === "object")) return undefined;
+      if (p in target) target = target[p];
+      else return undefined;
+    }
+    return target;
+  };
+
   globalThis.flattenObject = (obj, _d = 0) => {
     const flat = {};
     if (_d > 100) {
diff --git a/test/messages.test.js b/test/messages.test.js
index a61f15d..e3d634c 100644
--- a/test/messages.test.js
+++ b/test/messages.test.js
@@ -1,4 +1,4 @@
-import { beforeEach, describe, expect, jest, test } from "@jest/globals";
+import { beforeAll, describe, expect, jest, test } from "@jest/globals";
 import {
   AbilityCheckMessage,
   AbilitySaveMessage,
@@ -7,20 +7,7 @@ import {
   DeathSaveMessage,
   SkillMessage,
 } from "../src/messages";
-
-// fakes
-globalThis.setProperty = (object, key, value) => {
-  // split the key into parts, removing the last one
-  const parts = key.split(".");
-  const lastProp = parts.pop();
-  // recursively create objects out the key parts
-  const lastObj = parts.reduce((obj, prop) => {
-    if (!obj.hasOwnProperty(prop)) obj[prop] = {};
-    return obj[prop];
-  }, object);
-  // set the value using the last key part
-  lastObj[lastProp] = value;
-};
+import commonTestInit from "./common.js";
 
 function createActorWithEffects(...keyValuePairs) {
   const appliedEffects = keyValuePairs.map(createEffect);
@@ -52,6 +39,10 @@ function createItem(actionType, abilityMod) {
   };
 }
 
+beforeAll(() => {
+  commonTestInit();
+});
+
 describe("AttackMessage no legit active effects", () => {
   test("attack with no active effects should not add a message", () => {
     const actor = createActorWithEffects();