diff --git a/front/lib/api/workspace.ts b/front/lib/api/workspace.ts
index 72930066ac81..ce31dd71566c 100644
--- a/front/lib/api/workspace.ts
+++ b/front/lib/api/workspace.ts
@@ -127,7 +127,8 @@ export async function upgradeWorkspace(workspaceId: number) {
 
   plan.limits.dataSources.count = -1;
   plan.limits.dataSources.documents.count = -1;
-  plan.limits.dataSources.documents.sizeMb = -1;
+  // Enforce 1MB limitation even for upgraded workspaces.
+  plan.limits.dataSources.documents.sizeMb = 1;
   plan.limits.dataSources.managed = true;
   plan.limits.largeModels = true;
 
diff --git a/front/migrations/20230929_enforce_1mb_even_for_upgraded_workspaces.ts b/front/migrations/20230929_enforce_1mb_even_for_upgraded_workspaces.ts
new file mode 100644
index 000000000000..7f4cd3f0b65a
--- /dev/null
+++ b/front/migrations/20230929_enforce_1mb_even_for_upgraded_workspaces.ts
@@ -0,0 +1,58 @@
+import { Op } from "sequelize";
+
+import { planForWorkspace } from "@app/lib/auth";
+import { Workspace } from "@app/lib/models";
+
+const { LIVE = false } = process.env;
+
+async function main() {
+  console.log("Fetching Upgraded Worspaces...");
+  const workspaces = await Workspace.findAll({
+    where: {
+      upgradedAt: {
+        [Op.not]: null,
+      },
+    },
+  });
+  console.log(
+    `Found ${workspaces.length} workspaces for which to add largeModels = true`
+  );
+
+  const chunkSize = 16;
+  const chunks = [];
+  for (let i = 0; i < workspaces.length; i += chunkSize) {
+    chunks.push(workspaces.slice(i, i + chunkSize));
+  }
+
+  for (let i = 0; i < chunks.length; i++) {
+    console.log(`Processing chunk ${i}/${chunks.length}...`);
+    const chunk = chunks[i];
+    await Promise.all(
+      chunk.map((workspace: Workspace) => {
+        return set1MBLimit(!!LIVE, workspace);
+      })
+    );
+  }
+}
+
+async function set1MBLimit(live: boolean, workspace: Workspace) {
+  const plan = planForWorkspace(workspace);
+  plan.limits.dataSources.documents.sizeMb = 1;
+  if (live) {
+    await workspace.update({
+      plan: JSON.stringify(plan),
+    });
+  } else {
+    console.log(`Would have mutated ${workspace.sId}`);
+  }
+}
+
+main()
+  .then(() => {
+    console.log("done");
+    process.exit(0);
+  })
+  .catch((err) => {
+    console.error(err);
+    process.exit(1);
+  });
diff --git a/front/pages/api/v1/w/[wId]/data_sources/[name]/documents/[documentId]/index.ts b/front/pages/api/v1/w/[wId]/data_sources/[name]/documents/[documentId]/index.ts
index 401134481243..14ec7845cb4c 100644
--- a/front/pages/api/v1/w/[wId]/data_sources/[name]/documents/[documentId]/index.ts
+++ b/front/pages/api/v1/w/[wId]/data_sources/[name]/documents/[documentId]/index.ts
@@ -270,7 +270,7 @@ async function handler(
           api_error: {
             type: "data_source_quota_error",
             message:
-              "Data sources document upload size is limited to 1MB on our free plan. Contact team@dust.tt if you want to increase it.",
+              "Data sources document upload size is limited to 1MB. Contact team@dust.tt if you want to increase it.",
           },
         });
       }
diff --git a/front/pages/api/w/[wId]/data_sources/[name]/documents/[documentId]/index.ts b/front/pages/api/w/[wId]/data_sources/[name]/documents/[documentId]/index.ts
index 3777933d3f0a..6933f5791e9f 100644
--- a/front/pages/api/w/[wId]/data_sources/[name]/documents/[documentId]/index.ts
+++ b/front/pages/api/w/[wId]/data_sources/[name]/documents/[documentId]/index.ts
@@ -187,7 +187,7 @@ async function handler(
           api_error: {
             type: "data_source_quota_error",
             message:
-              "Data sources document upload size is limited to 1MB on our free plan. Contact team@dust.tt if you want to increase it.",
+              "Data sources document upload size is limited to 1MB. Contact team@dust.tt if you want to increase it.",
           },
         });
       }
diff --git a/front/pages/poke/[wId]/index.tsx b/front/pages/poke/[wId]/index.tsx
index c07dc290960d..2d20250a2165 100644
--- a/front/pages/poke/[wId]/index.tsx
+++ b/front/pages/poke/[wId]/index.tsx
@@ -248,14 +248,6 @@ const WorkspacePage = ({
     (ds) => !!ds.connectorProvider
   );
 
-  // @todo remove fallback on workspace plan
-  const isFullyUpgraded =
-    workspace.upgradedAt !== null ||
-    (workspace.plan?.limits.dataSources.count === -1 &&
-      workspace.plan?.limits.dataSources.documents.count === -1 &&
-      workspace.plan?.limits.dataSources.documents.sizeMb === -1 &&
-      workspace.plan?.limits.dataSources.managed === true);
-
   return (
     <div className="min-h-screen bg-structure-50">
       <PokeNavbar />
@@ -275,7 +267,7 @@ const WorkspacePage = ({
         <div className="flex justify-center">
           <div className="mx-2 w-1/3">
             <h2 className="text-md mb-4 font-bold">Plan:</h2>
-            {isFullyUpgraded ? (
+            {workspace.upgradedAt ? (
               <p className="mb-4 text-green-600">
                 This workspace was fully upgraded
                 {workspace.upgradedAt &&
@@ -294,18 +286,20 @@ const WorkspacePage = ({
                   label="Downgrade"
                   variant="secondaryWarning"
                   onClick={onDowngrade}
-                  disabled={!isFullyUpgraded || workspaceHasManagedDataSources}
+                  disabled={
+                    !workspace.upgradedAt || workspaceHasManagedDataSources
+                  }
                 />
 
                 <Button
                   label="Upgrade"
                   variant="secondary"
                   onClick={onUpgrade}
-                  disabled={isFullyUpgraded}
+                  disabled={!!workspace.upgradedAt}
                 />
               </div>
             </div>
-            {isFullyUpgraded && workspaceHasManagedDataSources && (
+            {workspace.upgradedAt && workspaceHasManagedDataSources && (
               <span className="mx-2 w-1/3">
                 <p className="text-warning mb-4 text-sm ">
                   Delete managed data sources before downgrading.
diff --git a/front/pages/w/[wId]/builder/data-sources/[name]/upsert.tsx b/front/pages/w/[wId]/builder/data-sources/[name]/upsert.tsx
index 0df87e106ad3..434dc0d4f73c 100644
--- a/front/pages/w/[wId]/builder/data-sources/[name]/upsert.tsx
+++ b/front/pages/w/[wId]/builder/data-sources/[name]/upsert.tsx
@@ -116,10 +116,27 @@ export default function DataSourceUpsert({
     }
   }, [dataSource.name, loadDocumentId, owner.sId]);
 
+  const alertDataSourcesLimit = () => {
+    window.alert(
+      "DataSource document upload size is limited to " +
+        `${owner.plan.limits.dataSources.documents.sizeMb}MB (of raw text)` +
+        ". Contact team@dust.tt if you want to increase this limit."
+    );
+  };
+
   const handleFileLoadedText = (e: any) => {
     const content = e.target.result;
-    setText(content);
     setUploading(false);
+
+    // Enforce plan limits: DataSource documents size.
+    if (
+      owner.plan.limits.dataSources.documents.sizeMb != -1 &&
+      text.length > 1024 * 1024 * owner.plan.limits.dataSources.documents.sizeMb
+    ) {
+      alertDataSourcesLimit();
+      return;
+    }
+    setText(content);
   };
 
   const handleFileLoadedPDF = async (e: any) => {
@@ -133,21 +150,21 @@ export default function DataSourceUpsert({
       const strings = content.items.map((item: any) => item.str);
       text += strings.join(" ") + "\n";
     }
-    setText(text);
+
     setUploading(false);
-  };
 
-  const handleFileUpload = async (file: File) => {
     // Enforce plan limits: DataSource documents size.
     if (
       owner.plan.limits.dataSources.documents.sizeMb != -1 &&
-      file.size > 1024 * 1024 * owner.plan.limits.dataSources.documents.sizeMb
+      text.length > 1024 * 1024 * owner.plan.limits.dataSources.documents.sizeMb
     ) {
-      window.alert(
-        "DataSource document upload size is limited to 1MB on our free plan. Contact team@dust.tt if you want to increase this limit."
-      );
+      alertDataSourcesLimit();
       return;
     }
+    setText(text);
+  };
+
+  const handleFileUpload = async (file: File) => {
     setUploading(true);
     if (file.type === "application/pdf") {
       const fileReader = new FileReader();