diff --git a/app/Jobs/ApplicationDeploymentJob.php b/app/Jobs/ApplicationDeploymentJob.php
index be7d747c46..42b2fc4831 100644
--- a/app/Jobs/ApplicationDeploymentJob.php
+++ b/app/Jobs/ApplicationDeploymentJob.php
@@ -1536,6 +1536,8 @@ class ApplicationDeploymentJob implements ShouldBeEncrypted, ShouldQueue
                 $this->rolling_update();
 
                 return true;
+            } elseif ($configurationDiff->isLegacyFallback()) {
+                $this->application_deployment_queue->addLogEntry('The last deployment stored no configuration snapshot. Rebuilding image.');
             } else {
                 $this->application_deployment_queue->addLogEntry('Build configuration changed. Rebuilding image.');
             }
diff --git a/app/Models/Application.php b/app/Models/Application.php
index bc59218bce..cd8d33893f 100644
--- a/app/Models/Application.php
+++ b/app/Models/Application.php
@@ -1491,23 +1491,13 @@ class Application extends BaseModel
 
     public function pendingDeploymentConfigurationDiff(): ConfigurationDiff
     {
-        $currentSnapshot = $this->deploymentConfigurationSnapshot();
-        $lastDeployment = $this->get_last_successful_deployment();
-
-        $previousSnapshot = $lastDeployment?->configuration_snapshot;
+        $previousSnapshot = $this->get_last_successful_deployment()?->configuration_snapshot;
 
         if (! $previousSnapshot) {
-            $oldConfigHash = data_get($this, 'config_hash');
-            $hasLegacyChange = $oldConfigHash === null || $oldConfigHash !== $this->legacyConfigurationHash();
-
-            if (! $hasLegacyChange) {
-                return ConfigurationDiff::unchanged();
-            }
-
-            $previousSnapshot = [];
+            return ConfigurationDiff::legacy();
         }
 
-        return app(ConfigurationDiffer::class)->diff(ApplicationConfigurationSnapshot::withoutPreviewVolumes($previousSnapshot, $this), $currentSnapshot);
+        return app(ConfigurationDiffer::class)->diff(ApplicationConfigurationSnapshot::withoutPreviewVolumes($previousSnapshot, $this), $this->deploymentConfigurationSnapshot());
     }
 
     public function hasPendingDeploymentConfigurationChanges(): bool
@@ -1530,7 +1520,7 @@ class Application extends BaseModel
         $this->refresh();
 
         if (! $deployment) {
-            $this->forceFill(['config_hash' => $this->legacyConfigurationHash()])->save();
+            $this->forceFill(['config_hash' => $this->deploymentConfigurationHash()])->save();
 
             return;
         }
@@ -1558,18 +1548,6 @@ class Application extends BaseModel
         $this->forceFill(['config_hash' => $hash])->save();
     }
 
-    private function legacyConfigurationHash(): string
-    {
-        $newConfigHash = base64_encode($this->fqdn.json_encode($this->noindexDomains()->all()).$this->git_repository.$this->git_branch.$this->git_commit_sha.$this->build_pack.$this->static_image.$this->install_command.$this->build_command.$this->start_command.$this->ports_exposes.$this->ports_mappings.$this->custom_network_aliases.$this->base_directory.$this->publish_directory.$this->dockerfile.$this->dockerfile_location.$this->custom_labels.$this->custom_docker_run_options.$this->dockerfile_target_build.$this->redirect.$this->custom_nginx_configuration.$this->settings?->use_build_secrets.$this->settings?->inject_build_args_to_dockerfile.$this->settings?->include_source_commit_in_build);
-        if ($this->pull_request_id === 0 || $this->pull_request_id === null) {
-            $newConfigHash .= json_encode($this->environment_variables()->get(['value',  'is_multiline', 'is_literal', 'is_buildtime', 'is_runtime'])->makeVisible('value')->sort());
-        } else {
-            $newConfigHash .= json_encode($this->environment_variables_preview()->get(['value', 'is_multiline', 'is_literal', 'is_buildtime', 'is_runtime'])->makeVisible('value')->sort());
-        }
-
-        return md5($newConfigHash);
-    }
-
     public function customRepository()
     {
         return convertGitUrl($this->git_repository, $this->deploymentType(), $this->source);
diff --git a/app/Services/DeploymentConfiguration/ConfigurationDiff.php b/app/Services/DeploymentConfiguration/ConfigurationDiff.php
index 3f0477ba35..b648331c53 100644
--- a/app/Services/DeploymentConfiguration/ConfigurationDiff.php
+++ b/app/Services/DeploymentConfiguration/ConfigurationDiff.php
@@ -17,25 +17,13 @@ class ConfigurationDiff
         return new self;
     }
 
-    public static function legacy(bool $changed): self
+    /**
+     * The last deployment stored no configuration snapshot (it ran before v4.1), so the
+     * deployed configuration is unknown. Report no changes, but build on the next deployment.
+     */
+    public static function legacy(): self
     {
-        if (! $changed) {
-            return self::unchanged();
-        }
-
-        return new self([
-            [
-                'key' => 'legacy.configuration',
-                'section' => 'configuration',
-                'section_label' => 'Configuration',
-                'label' => 'Configuration',
-                'type' => 'changed',
-                'impact' => 'build',
-                'sensitive' => false,
-                'old_display_value' => 'Previously deployed configuration',
-                'new_display_value' => 'Current configuration',
-            ],
-        ], true);
+        return new self(legacyFallback: true);
     }
 
     /**
@@ -63,7 +51,7 @@ class ConfigurationDiff
 
     public function requiresBuild(): bool
     {
-        return collect($this->changes)->contains(fn (array $change): bool => $change['impact'] === 'build');
+        return $this->legacyFallback || collect($this->changes)->contains(fn (array $change): bool => $change['impact'] === 'build');
     }
 
     public function requiresRedeploy(): bool
diff --git a/tests/Feature/ApplicationConfigurationChangedTest.php b/tests/Feature/ApplicationConfigurationChangedTest.php
index 4650e2b12c..9c21e48fda 100644
--- a/tests/Feature/ApplicationConfigurationChangedTest.php
+++ b/tests/Feature/ApplicationConfigurationChangedTest.php
@@ -135,13 +135,12 @@ it('does not flag applications whose older snapshot omitted noindex domains', fu
     expect($application->refresh()->pendingDeploymentConfigurationDiff()->isChanged())->toBeFalse();
 });
 
-it('checks legacy preview deployment configuration hash using preview environment variable query', function () {
+it('does not report changes for applications deployed before configuration snapshots existed', function () {
     $application = configurationChangedTestApplication();
 
     EnvironmentVariable::create([
-        'key' => 'APP_ENV',
-        'value' => 'preview',
-        'is_preview' => true,
+        'key' => 'APP_SECRET',
+        'value' => 'secret',
         'is_multiline' => false,
         'is_literal' => false,
         'is_buildtime' => true,
@@ -150,29 +149,28 @@ it('checks legacy preview deployment configuration hash using preview environmen
         'resourceable_id' => $application->id,
     ]);
 
-    $application->forceFill([
-        'config_hash' => 'legacy-hash',
-        'pull_request_id' => 123,
-    ]);
+    configurationChangedDeployment($application);
+    $application->forceFill(['config_hash' => md5('hash written by an older Coolify version')])->save();
 
-    $diff = $application->pendingDeploymentConfigurationDiff();
+    $diff = $application->refresh()->pendingDeploymentConfigurationDiff();
 
-    expect($diff->isChanged())->toBeTrue()
-        ->and($diff->count())->toBeGreaterThan(0);
+    expect($diff->isChanged())->toBeFalse()
+        ->and($diff->count())->toBe(0)
+        ->and($diff->isLegacyFallback())->toBeTrue()
+        ->and($diff->requiresBuild())->toBeTrue();
 });
 
-it('falls back to real diff against empty snapshot when no deployment snapshot exists', function () {
+it('compares with the deployment snapshot once an application without one is deployed again', function () {
     $application = configurationChangedTestApplication();
-    $application->isConfigurationChanged(save: true);
-
-    expect($application->refresh()->pendingDeploymentConfigurationDiff()->isChanged())->toBeFalse();
+    configurationChangedDeployment($application);
+    $application->forceFill(['config_hash' => md5('hash written by an older Coolify version')])->save();
 
+    $application->markDeploymentConfigurationApplied(configurationChangedDeployment($application));
     $application->update(['build_command' => 'pnpm build']);
 
     $diff = $application->refresh()->pendingDeploymentConfigurationDiff();
 
-    expect($diff->isChanged())->toBeTrue()
-        ->and($diff->isLegacyFallback())->toBeFalse()
-        ->and($diff->count())->toBeGreaterThan(0)
-        ->and(collect($diff->changes())->pluck('label')->toArray())->toContain('Build command');
+    expect($diff->isLegacyFallback())->toBeFalse()
+        ->and(collect($diff->changes())->pluck('label')->all())->toBe(['Build command'])
+        ->and($diff->requiresBuild())->toBeTrue();
 });