diff --git a/lib/workers/repository/update/branch/index.spec.ts b/lib/workers/repository/update/branch/index.spec.ts
index 9652a2439c06e4805535c09f45187205333b6521..a54172896054390a6330090cc52ebb2effb09d68 100644
--- a/lib/workers/repository/update/branch/index.spec.ts
+++ b/lib/workers/repository/update/branch/index.spec.ts
@@ -940,6 +940,10 @@ describe('workers/repository/update/branch/index', () => {
         prNo: undefined,
         result: 'pr-edited',
       });
+      expect(logger.info).toHaveBeenCalledWith(
+        `DRY-RUN: Would update existing PR to indicate that rebasing is not possible`
+      );
+      expect(platform.updatePr).toHaveBeenCalledTimes(0);
     });
 
     it('branch pr no schedule lockfile (dry run)', async () => {
diff --git a/lib/workers/repository/update/branch/index.ts b/lib/workers/repository/update/branch/index.ts
index d2d2bfe6cede900d91923faf3e77a26ef204e322..53f1ef2cf9f1e0016dc53331df9800c6b3347aa6 100644
--- a/lib/workers/repository/update/branch/index.ts
+++ b/lib/workers/repository/update/branch/index.ts
@@ -198,15 +198,21 @@ export async function processBranch(
             });
             const newBodyHash = hashBody(newBody);
             if (newBodyHash !== branchPr.bodyStruct?.hash) {
-              logger.debug(
-                'Updating existing PR to indicate that rebasing is not possible'
-              );
-              await platform.updatePr({
-                number: branchPr.number,
-                prTitle: branchPr.title,
-                prBody: newBody,
-                platformOptions: getPlatformPrOptions(config),
-              });
+              if (GlobalConfig.get('dryRun')) {
+                logger.info(
+                  `DRY-RUN: Would update existing PR to indicate that rebasing is not possible`
+                );
+              } else {
+                logger.debug(
+                  'Updating existing PR to indicate that rebasing is not possible'
+                );
+                await platform.updatePr({
+                  number: branchPr.number,
+                  prTitle: branchPr.title,
+                  prBody: newBody,
+                  platformOptions: getPlatformPrOptions(config),
+                });
+              }
             }
             return {
               branchExists,