diff --git a/lib/context/repoContext.js b/lib/context/repoContext.js
index 0d419b1fa..fab51d82c 100644
--- a/lib/context/repoContext.js
+++ b/lib/context/repoContext.js
@@ -2,6 +2,7 @@
 
 'use strict';
 
+const Lock = require('lock').Lock;
 const teamConfigs = require('../teamconfigs');
 const { obtainTeamContext } = require('./teamContext');
 const initRepoLabels = require('./initRepoLabels');
@@ -106,9 +107,31 @@ const initRepoContext = async (context, config) => {
     }
   };
 
+  const lock = Lock();
+
   return Object.assign(repoContext, {
     updateStatusCheckFromLabels,
 
+    lockPR: (context, callback) =>
+      new Promise((resolve, reject) => {
+        const pr = context.payload.pull_request;
+        console.log('try to lock pr', { id: pr.id });
+        lock(pr.id, async (release) => {
+          console.log('pr lock acquired', { id: pr.id });
+          try {
+            await callback();
+          } catch (err) {
+            console.log('release pr (with error)', { id: pr.id });
+            release()();
+            reject(err);
+            return;
+          }
+          console.log('release pr', { id: pr.id });
+          release()();
+          resolve();
+        });
+      }),
+
     updateReviewStatus: async (
       context,
       reviewGroup,
@@ -153,7 +176,7 @@ const initRepoContext = async (context, config) => {
         newLabels: [...newLabels],
       });
 
-      if (process.env.DRY_RUN) return;
+      // if (process.env.DRY_RUN) return;
 
       if (toAdd.size || toDelete.size) {
         await context.github.issues.replaceLabels(
diff --git a/lib/index.js b/lib/index.js
index 81fff9247..f87e8ca9d 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -26,126 +26,134 @@ module.exports = (app) => {
     const repoContext = await obtainRepoContext(context);
     if (!repoContext) return;
 
-    await Promise.all([
-      autoAssignPRToCreator(repoContext, context),
-      editOpenedPR(repoContext, context),
-      lintPR(repoContext, context),
-      repoContext.updateReviewStatus(context, 'dev', {
-        add: ['needsReview'],
-      }),
-    ]);
+    return repoContext.lockPR(context, async () => {
+      await Promise.all([
+        autoAssignPRToCreator(repoContext, context),
+        editOpenedPR(repoContext, context),
+        lintPR(repoContext, context),
+        repoContext.updateReviewStatus(context, 'dev', {
+          add: ['needsReview'],
+        }),
+      ]);
+    });
   });
 
   app.on('pull_request.review_requested', async (context) => {
     const repoContext = await obtainRepoContext(context);
     if (!repoContext) return;
-    const sender = context.payload.sender;
 
-    // ignore if sender is self (dismissed review rerequest review)
-    if (sender.type === 'Bot') return;
-
-    const pr = context.payload.pull_request;
-    const reviewer = context.payload.requested_reviewer;
-
-    const reviewerGroup = repoContext.getReviewerGroup(reviewer.login);
-    const shouldWait = false;
-    // repoContext.reviewShouldWait(reviewerGroup, pr.requested_reviewers, { includesWaitForGroups: true });
+    return repoContext.lockPR(context, async () => {
+      const sender = context.payload.sender;
 
-    if (repoContext.config.labels.review[reviewerGroup]) {
-      const { data: reviews } = await context.github.pullRequests.listReviews(
-        context.issue({ per_page: 50 })
-      );
-      const hasChangesRequestedInReviews = reviews.some(
-        (review) =>
-          repoContext.getReviewerGroup(review.user.login) === reviewerGroup &&
-          review.state === 'REQUEST_CHANGES' &&
-          // In case this is a rerequest for review
-          review.user.login !== reviewer.login
-      );
+      // ignore if sender is self (dismissed review rerequest review)
+      if (sender.type === 'Bot') return;
 
-      if (!hasChangesRequestedInReviews) {
-        repoContext.updateReviewStatus(context, reviewerGroup, {
-          add: ['needsReview', !shouldWait && 'requested'],
-          remove: ['approved', 'changesRequested'],
-        });
+      const pr = context.payload.pull_request;
+      const reviewer = context.payload.requested_reviewer;
+
+      const reviewerGroup = repoContext.getReviewerGroup(reviewer.login);
+      const shouldWait = false;
+      // repoContext.reviewShouldWait(reviewerGroup, pr.requested_reviewers, { includesWaitForGroups: true });
+
+      if (repoContext.config.labels.review[reviewerGroup]) {
+        const { data: reviews } = await context.github.pullRequests.listReviews(
+          context.issue({ per_page: 50 })
+        );
+        const hasChangesRequestedInReviews = reviews.some(
+          (review) =>
+            repoContext.getReviewerGroup(review.user.login) === reviewerGroup &&
+            review.state === 'REQUEST_CHANGES' &&
+            // In case this is a rerequest for review
+            review.user.login !== reviewer.login
+        );
+
+        if (!hasChangesRequestedInReviews) {
+          repoContext.updateReviewStatus(context, reviewerGroup, {
+            add: ['needsReview', !shouldWait && 'requested'],
+            remove: ['approved', 'changesRequested'],
+          });
+        }
       }
-    }
 
-    if (sender.login === reviewer.login) return;
+      if (sender.login === reviewer.login) return;
 
-    if (!shouldWait) {
-      repoContext.slack.postMessage(
-        reviewer.login,
-        `:eyes: ${repoContext.slack.mention(
-          sender.login
-        )} requests your review on ${pr.html_url} !\n> ${pr.title}`
-      );
-    }
+      if (!shouldWait) {
+        repoContext.slack.postMessage(
+          reviewer.login,
+          `:eyes: ${repoContext.slack.mention(
+            sender.login
+          )} requests your review on ${pr.html_url} !\n> ${pr.title}`
+        );
+      }
+    });
   });
 
   app.on('pull_request.review_request_removed', async (context) => {
     const repoContext = await obtainRepoContext(context);
     if (!repoContext) return;
-    const sender = context.payload.sender;
-    const pr = context.payload.pull_request;
-    const reviewer = context.payload.requested_reviewer;
 
-    const reviewerGroup = repoContext.getReviewerGroup(reviewer.login);
+    return repoContext.lockPR(context, async () => {
+      const sender = context.payload.sender;
+      const pr = context.payload.pull_request;
+      const reviewer = context.payload.requested_reviewer;
 
-    const hasRequestedReviewsForGroup = repoContext.reviewShouldWait(
-      reviewerGroup,
-      pr.requested_reviewers,
-      {
-        includesReviewerGroup: true,
-      }
-    );
+      const reviewerGroup = repoContext.getReviewerGroup(reviewer.login);
 
-    if (repoContext.config.labels.review[reviewerGroup]) {
-      const { data: reviews } = await context.github.pullRequests.listReviews(
-        context.issue({ per_page: 50 })
+      const hasRequestedReviewsForGroup = repoContext.reviewShouldWait(
+        reviewerGroup,
+        pr.requested_reviewers,
+        {
+          includesReviewerGroup: true,
+        }
       );
 
-      const hasChangesRequestedInReviews = reviews.some(
-        (review) =>
-          repoContext.getReviewerGroup(review.user.login) === reviewerGroup &&
-          review.state === 'REQUEST_CHANGES'
-      );
+      if (repoContext.config.labels.review[reviewerGroup]) {
+        const { data: reviews } = await context.github.pullRequests.listReviews(
+          context.issue({ per_page: 50 })
+        );
 
-      const hasApprovedInReviews = reviews.some(
-        (review) =>
-          repoContext.getReviewerGroup(review.user.login) === reviewerGroup &&
-          review.state === 'APPROVED'
-      );
+        const hasChangesRequestedInReviews = reviews.some(
+          (review) =>
+            repoContext.getReviewerGroup(review.user.login) === reviewerGroup &&
+            review.state === 'REQUEST_CHANGES'
+        );
+
+        const hasApprovedInReviews = reviews.some(
+          (review) =>
+            repoContext.getReviewerGroup(review.user.login) === reviewerGroup &&
+            review.state === 'APPROVED'
+        );
 
-      const approved =
-        !hasRequestedReviewsForGroup &&
-        !hasChangesRequestedInReviews &&
-        hasApprovedInReviews;
-      repoContext.updateReviewStatus(context, reviewerGroup, {
-        add: [
-          // if changes requested by the one which requests was removed
-          hasChangesRequestedInReviews && 'changesRequested',
-          // if was already approved by another member in the group and has no other requests waiting
-          approved && 'approved',
-        ],
-        // remove labels if has no other requests waiting
-        remove: [
-          approved && 'needsReview',
+        const approved =
           !hasRequestedReviewsForGroup &&
-            !hasChangesRequestedInReviews &&
-            'requested',
-        ],
-      });
-    }
+          !hasChangesRequestedInReviews &&
+          hasApprovedInReviews;
+        repoContext.updateReviewStatus(context, reviewerGroup, {
+          add: [
+            // if changes requested by the one which requests was removed
+            hasChangesRequestedInReviews && 'changesRequested',
+            // if was already approved by another member in the group and has no other requests waiting
+            approved && 'approved',
+          ],
+          // remove labels if has no other requests waiting
+          remove: [
+            approved && 'needsReview',
+            !hasRequestedReviewsForGroup &&
+              !hasChangesRequestedInReviews &&
+              'requested',
+          ],
+        });
+      }
 
-    if (sender.login === reviewer.login) return;
+      if (sender.login === reviewer.login) return;
 
-    repoContext.slack.postMessage(
-      reviewer.login,
-      `:skull_and_crossbones: ${repoContext.slack.mention(
-        sender.login
-      )} removed the request for your review on ${pr.html_url}`
-    );
+      repoContext.slack.postMessage(
+        reviewer.login,
+        `:skull_and_crossbones: ${repoContext.slack.mention(
+          sender.login
+        )} removed the request for your review on ${pr.html_url}`
+      );
+    });
   });
 
   // app.on('pull_request.closed', async context => {
@@ -159,111 +167,117 @@ module.exports = (app) => {
   app.on('pull_request_review.submitted', async (context) => {
     const repoContext = await obtainRepoContext(context);
     if (!repoContext) return;
-    const pr = context.payload.pull_request;
-    const { user: reviewer, state } = context.payload.review;
-    if (pr.user.login === reviewer.login) return;
 
-    const reviewerGroup = repoContext.getReviewerGroup(reviewer.login);
-
-    if (reviewerGroup && repoContext.config.labels.review[reviewerGroup]) {
-      const hasRequestedReviewsForGroup = repoContext.reviewShouldWait(
-        reviewerGroup,
-        pr.requested_reviewers,
-        {
-          includesReviewerGroup: true,
-          // TODO reenable this when accepted can notify request review to slack (dev accepted => design requested) and flag to disable for label (approved design ; still waiting for dev ?)
-          // includesWaitForGroups: true,
-        }
-      );
-      const { data: reviews } = await context.github.pullRequests.listReviews(
-        context.issue({ per_page: 50 })
-      );
-      const hasChangesRequestedInReviews = reviews.some(
-        (review) =>
-          repoContext.getReviewerGroup(review.user.login) === reviewerGroup &&
-          review.state === 'REQUEST_CHANGES'
-      );
-
-      const approved =
-        !hasRequestedReviewsForGroup &&
-        !hasChangesRequestedInReviews &&
-        state === 'approved';
-      repoContext.updateReviewStatus(context, reviewerGroup, {
-        add: [
-          approved && 'approved',
-          state === 'changes_requested' && 'changesRequested',
-        ],
-        remove: [
-          approved && 'needsReview',
-          !(hasRequestedReviewsForGroup || state === 'changes_requested') &&
-            'requested',
-          state === 'approved' &&
-            !hasChangesRequestedInReviews &&
-            'changesRequested',
-          state === 'changes_requested' && 'approved',
-        ],
-      });
-    }
+    return repoContext.lockPR(context, async () => {
+      const pr = context.payload.pull_request;
+      const { user: reviewer, state } = context.payload.review;
+      if (pr.user.login === reviewer.login) return;
+
+      const reviewerGroup = repoContext.getReviewerGroup(reviewer.login);
+
+      if (reviewerGroup && repoContext.config.labels.review[reviewerGroup]) {
+        const hasRequestedReviewsForGroup = repoContext.reviewShouldWait(
+          reviewerGroup,
+          pr.requested_reviewers,
+          {
+            includesReviewerGroup: true,
+            // TODO reenable this when accepted can notify request review to slack (dev accepted => design requested) and flag to disable for label (approved design ; still waiting for dev ?)
+            // includesWaitForGroups: true,
+          }
+        );
+        const { data: reviews } = await context.github.pullRequests.listReviews(
+          context.issue({ per_page: 50 })
+        );
+        const hasChangesRequestedInReviews = reviews.some(
+          (review) =>
+            repoContext.getReviewerGroup(review.user.login) === reviewerGroup &&
+            review.state === 'REQUEST_CHANGES'
+        );
+
+        const approved =
+          !hasRequestedReviewsForGroup &&
+          !hasChangesRequestedInReviews &&
+          state === 'approved';
+        repoContext.updateReviewStatus(context, reviewerGroup, {
+          add: [
+            approved && 'approved',
+            state === 'changes_requested' && 'changesRequested',
+          ],
+          remove: [
+            approved && 'needsReview',
+            !(hasRequestedReviewsForGroup || state === 'changes_requested') &&
+              'requested',
+            state === 'approved' &&
+              !hasChangesRequestedInReviews &&
+              'changesRequested',
+            state === 'changes_requested' && 'approved',
+          ],
+        });
+      }
 
-    const mention = repoContext.slack.mention(reviewer.login);
-    const prUrl = pr.html_url;
+      const mention = repoContext.slack.mention(reviewer.login);
+      const prUrl = pr.html_url;
 
-    const message = (() => {
-      if (state === 'changes_requested') {
-        return `:x: ${mention} requests changes on ${prUrl}`;
-      }
-      if (state === 'approved') {
-        return `:clap: :white_check_mark: ${mention} approves ${prUrl}`;
-      }
-      return `:speech_balloon: ${mention} commented on ${prUrl}`;
-    })();
+      const message = (() => {
+        if (state === 'changes_requested') {
+          return `:x: ${mention} requests changes on ${prUrl}`;
+        }
+        if (state === 'approved') {
+          return `:clap: :white_check_mark: ${mention} approves ${prUrl}`;
+        }
+        return `:speech_balloon: ${mention} commented on ${prUrl}`;
+      })();
 
-    repoContext.slack.postMessage(pr.user.login, message);
+      repoContext.slack.postMessage(pr.user.login, message);
+    });
   });
 
   app.on('pull_request_review.dismissed', async (context) => {
     const repoContext = await obtainRepoContext(context);
     if (!repoContext) return;
-    const sender = context.payload.sender;
-    const pr = context.payload.pull_request;
-    const reviewer = context.payload.review.user;
 
-    const reviewerGroup = repoContext.getReviewerGroup(reviewer.login);
+    return repoContext.lockPR(context, async () => {
+      const sender = context.payload.sender;
+      const pr = context.payload.pull_request;
+      const reviewer = context.payload.review.user;
 
-    if (reviewerGroup && repoContext.config.labels.review[reviewerGroup]) {
-      const { data: reviews } = await context.github.pullRequests.listReviews(
-        context.issue({ per_page: 50 })
-      );
-      const hasChangesRequestedInReviews = reviews.some(
-        (review) =>
-          repoContext.getReviewerGroup(review.user.login) === reviewerGroup &&
-          review.state === 'REQUEST_CHANGES'
-      );
+      const reviewerGroup = repoContext.getReviewerGroup(reviewer.login);
 
-      repoContext.updateReviewStatus(context, reviewerGroup, {
-        add: ['needsReview', 'requested'],
-        remove: [
-          !hasChangesRequestedInReviews && 'changesRequested',
-          'approved',
-        ],
-      });
-    }
+      if (reviewerGroup && repoContext.config.labels.review[reviewerGroup]) {
+        const { data: reviews } = await context.github.pullRequests.listReviews(
+          context.issue({ per_page: 50 })
+        );
+        const hasChangesRequestedInReviews = reviews.some(
+          (review) =>
+            repoContext.getReviewerGroup(review.user.login) === reviewerGroup &&
+            review.state === 'REQUEST_CHANGES'
+        );
 
-    if (sender.login === reviewer.login) {
-      repoContext.slack.postMessage(
-        pr.user.login,
-        `:skull: ${repoContext.slack.mention(
-          reviewer.login
-        )} dismissed his review on ${pr.html_url}`
-      );
-    } else {
-      repoContext.slack.postMessage(
-        reviewer.login,
-        `:skull: ${repoContext.slack.mention(
-          sender.login
-        )} dismissed your review on ${pr.html_url}`
-      );
-    }
+        repoContext.updateReviewStatus(context, reviewerGroup, {
+          add: ['needsReview', 'requested'],
+          remove: [
+            !hasChangesRequestedInReviews && 'changesRequested',
+            'approved',
+          ],
+        });
+      }
+
+      if (sender.login === reviewer.login) {
+        repoContext.slack.postMessage(
+          pr.user.login,
+          `:skull: ${repoContext.slack.mention(
+            reviewer.login
+          )} dismissed his review on ${pr.html_url}`
+        );
+      } else {
+        repoContext.slack.postMessage(
+          reviewer.login,
+          `:skull: ${repoContext.slack.mention(
+            sender.login
+          )} dismissed your review on ${pr.html_url}`
+        );
+      }
+    });
   });
 
   app.on(
@@ -275,7 +289,9 @@ module.exports = (app) => {
       const repoContext = await obtainRepoContext(context);
       if (!repoContext) return;
 
-      await repoContext.updateStatusCheckFromLabels(context);
+      return repoContext.lockPR(context, async () => {
+        await repoContext.updateStatusCheckFromLabels(context);
+      });
     }
   );
 
@@ -283,19 +299,23 @@ module.exports = (app) => {
     const repoContext = await obtainRepoContext(context);
     if (!repoContext) return;
 
-    await Promise.all([
-      editOpenedPR(repoContext, context),
-      repoContext.addStatusCheckToLatestCommit(context),
-    ]);
+    return repoContext.lockPR(context, async () => {
+      await Promise.all([
+        editOpenedPR(repoContext, context),
+        repoContext.addStatusCheckToLatestCommit(context),
+      ]);
+    });
   });
 
   app.on('pull_request.edited', async (context) => {
     const repoContext = await obtainRepoContext(context);
     if (!repoContext) return;
 
-    await Promise.all([
-      editOpenedPR(repoContext, context),
-      lintPR(repoContext, context),
-    ]);
+    return repoContext.lockPR(context, async () => {
+      await Promise.all([
+        editOpenedPR(repoContext, context),
+        lintPR(repoContext, context),
+      ]);
+    });
   });
 };
diff --git a/lib/teamconfigs/christophehurpeau.js b/lib/teamconfigs/christophehurpeau.js
index 91c3daf2c..20c69e40e 100644
--- a/lib/teamconfigs/christophehurpeau.js
+++ b/lib/teamconfigs/christophehurpeau.js
@@ -20,6 +20,7 @@ module.exports = {
   },
   dev: {
     christophehurpeau: 'christophe@hurpeau.com',
+    'chris-reviewflow': 'christophe.hurpeau+reviewflow@gmail.com',
   },
   waitForGroups: {
     dev: [],
diff --git a/package.json b/package.json
index 16572ba14..d149de227 100644
--- a/package.json
+++ b/package.json
@@ -57,6 +57,7 @@
   },
   "dependencies": {
     "@slack/client": "4.8.0",
+    "lock": "^1.1.0",
     "probot": "7.4.0",
     "probot-config": "probot/probot-config#def82e6b324439f08c1c630c4f3cb57bab689979"
   },
diff --git a/yarn.lock b/yarn.lock
index 44458ba65..a22a55cfe 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -4187,6 +4187,11 @@ locate-path@^3.0.0:
     p-locate "^3.0.0"
     path-exists "^3.0.0"
 
+lock@^1.1.0:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/lock/-/lock-1.1.0.tgz#53157499d1653b136ca66451071fca615703fa55"
+  integrity sha1-UxV0mdFlOxNspmRRBx/KYVcD+lU=
+
 lodash._basecopy@^3.0.0:
   version "3.0.1"
   resolved "https://registry.yarnpkg.com/lodash._basecopy/-/lodash._basecopy-3.0.1.tgz#8da0e6a876cf344c0ad8a54882111dd3c5c7ca36"