diff --git a/Samples/iOS-Swift/iOS-Swift-UITests/LaunchUITests.swift b/Samples/iOS-Swift/iOS-Swift-UITests/LaunchUITests.swift
index 4091f8c584e..58285bb46b1 100644
--- a/Samples/iOS-Swift/iOS-Swift-UITests/LaunchUITests.swift
+++ b/Samples/iOS-Swift/iOS-Swift-UITests/LaunchUITests.swift
@@ -92,6 +92,20 @@ class LaunchUITests: BaseUITest {
         XCTAssertTrue(0.5 > frozenFramesPercentage, "Too many frozen frames.")
     }
     
+    func testCorruptEnvelope() {
+        // This is to prevent https://github.com/getsentry/sentry-cocoa/issues/4280
+        // Tapping "Corrupt Envelope" will try to capture an envelope but it closes the app
+        // in the middle of the process. For 8.33.0 this would generate a corrupted envelope.
+        // 8.35.0+ reverts to writing envelopes atomically, so that in this scenario no envelope is written, as is expected.
+        // By opening the app again we can check whether the SDK can handle such scenario.
+        app.buttons["Corrupt Envelope"].tap()
+        XCTAssertEqual(app.state, .notRunning)
+        
+        app.launch()
+        XCTAssertEqual(app.state, .runningForeground)
+        app.tabBars.firstMatch.waitForExistence("App did not open again")
+    }
+    
     func testCheckTotalFrames() {
         app.buttons["Extra"].tap()
         
diff --git a/Samples/iOS-Swift/iOS-Swift.xcodeproj/project.pbxproj b/Samples/iOS-Swift/iOS-Swift.xcodeproj/project.pbxproj
index aa60769d555..9c55e518915 100644
--- a/Samples/iOS-Swift/iOS-Swift.xcodeproj/project.pbxproj
+++ b/Samples/iOS-Swift/iOS-Swift.xcodeproj/project.pbxproj
@@ -329,6 +329,7 @@
 		D8269A42274C095F00BD5BD5 /* Base */ = {isa = PBXFileReference; lastKnownFileType = file.storyboard; name = Base; path = Base.lproj/Main.storyboard; sourceTree = "<group>"; };
 		D8269A49274C096000BD5BD5 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
 		D8269A5C274C108100BD5BD5 /* iOS13-Swift.entitlements */ = {isa = PBXFileReference; lastKnownFileType = text.plist.entitlements; path = "iOS13-Swift.entitlements"; sourceTree = "<group>"; };
+		D82915932C889F1800A6CDD4 /* SentryCocoaPrivate.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SentryCocoaPrivate.h; sourceTree = "<group>"; };
 		D83A30DF279F1F5C00372D0A /* fatal-error-binary-images-message2.json */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.json; name = "fatal-error-binary-images-message2.json"; path = "../../../Tests/Resources/fatal-error-binary-images-message2.json"; sourceTree = "<group>"; };
 		D840D520273A07F400CDF142 /* iOS-SwiftClip.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = "iOS-SwiftClip.app"; sourceTree = BUILT_PRODUCTS_DIR; };
 		D840D522273A07F400CDF142 /* AppDelegate.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppDelegate.swift; sourceTree = "<group>"; };
@@ -611,6 +612,7 @@
 				D8F01DF02A1377D0008F4996 /* SentryExposure.h */,
 				D8832B192AF4FE2000C522B0 /* SentryUIApplication.h */,
 				629EC8AC2B0B537400858855 /* TriggerAppHang.swift */,
+				D82915932C889F1800A6CDD4 /* SentryCocoaPrivate.h */,
 			);
 			path = Tools;
 			sourceTree = "<group>";
diff --git a/Samples/iOS-Swift/iOS-Swift/Base.lproj/Main.storyboard b/Samples/iOS-Swift/iOS-Swift/Base.lproj/Main.storyboard
index c3745fcac53..97001ac0a30 100644
--- a/Samples/iOS-Swift/iOS-Swift/Base.lproj/Main.storyboard
+++ b/Samples/iOS-Swift/iOS-Swift/Base.lproj/Main.storyboard
@@ -711,13 +711,13 @@
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                         <subviews>
                             <stackView opaque="NO" contentMode="scaleToFill" axis="vertical" translatesAutoresizingMaskIntoConstraints="NO" id="40A-vG-dFA">
-                                <rect key="frame" x="0.0" y="64" width="320" height="246.5"/>
+                                <rect key="frame" x="0.0" y="64" width="320" height="268"/>
                                 <subviews>
                                     <stackView opaque="NO" contentMode="scaleToFill" distribution="fillEqually" translatesAutoresizingMaskIntoConstraints="NO" id="fn9-mQ-2PY">
-                                        <rect key="frame" x="0.0" y="0.0" width="320" height="118.5"/>
+                                        <rect key="frame" x="0.0" y="0.0" width="320" height="140"/>
                                         <subviews>
                                             <stackView opaque="NO" contentMode="scaleToFill" axis="vertical" distribution="equalSpacing" translatesAutoresizingMaskIntoConstraints="NO" id="Q2k-6Y-RnD">
-                                                <rect key="frame" x="0.0" y="0.0" width="160" height="118.5"/>
+                                                <rect key="frame" x="0.0" y="0.0" width="160" height="140"/>
                                                 <subviews>
                                                     <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="system" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="NFC-V3-lgW">
                                                         <rect key="frame" x="0.0" y="0.0" width="160" height="28"/>
@@ -728,7 +728,7 @@
                                                         </connections>
                                                     </button>
                                                     <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="system" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="Llv-Yz-cwF">
-                                                        <rect key="frame" x="0.0" y="30" width="160" height="28"/>
+                                                        <rect key="frame" x="0.0" y="28" width="160" height="28"/>
                                                         <fontDescription key="fontDescription" type="system" pointSize="13"/>
                                                         <state key="normal" title="Capture NSException"/>
                                                         <connections>
@@ -736,7 +736,7 @@
                                                         </connections>
                                                     </button>
                                                     <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="system" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="wJ4-gS-64G" userLabel="fatalError">
-                                                        <rect key="frame" x="0.0" y="60.5" width="160" height="28"/>
+                                                        <rect key="frame" x="0.0" y="56" width="160" height="28"/>
                                                         <fontDescription key="fontDescription" type="system" pointSize="13"/>
                                                         <state key="normal" title="Throw FatalError"/>
                                                         <connections>
@@ -744,17 +744,25 @@
                                                         </connections>
                                                     </button>
                                                     <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="system" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="NYx-6R-0bb">
-                                                        <rect key="frame" x="0.0" y="90.5" width="160" height="28"/>
+                                                        <rect key="frame" x="0.0" y="84" width="160" height="28"/>
                                                         <fontDescription key="fontDescription" type="system" pointSize="13"/>
                                                         <state key="normal" title="OOM crash"/>
                                                         <connections>
                                                             <action selector="oomCrash:" destination="QmU-DD-itF" eventType="touchUpInside" id="U4n-XL-dJf"/>
                                                         </connections>
                                                     </button>
+                                                    <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="system" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="rJk-dh-q7U">
+                                                        <rect key="frame" x="0.0" y="112" width="160" height="28"/>
+                                                        <fontDescription key="fontDescription" type="system" pointSize="13"/>
+                                                        <state key="normal" title="Corrupt Envelope"/>
+                                                        <connections>
+                                                            <action selector="corruptEnvelope:" destination="QmU-DD-itF" eventType="touchUpInside" id="5hY-Uf-cey"/>
+                                                        </connections>
+                                                    </button>
                                                 </subviews>
                                             </stackView>
                                             <stackView opaque="NO" contentMode="scaleToFill" axis="vertical" distribution="equalSpacing" translatesAutoresizingMaskIntoConstraints="NO" id="2CV-VI-MDY">
-                                                <rect key="frame" x="160" y="0.0" width="160" height="118.5"/>
+                                                <rect key="frame" x="160" y="0.0" width="160" height="140"/>
                                                 <subviews>
                                                     <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="system" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="Zbo-2T-1Zm">
                                                         <rect key="frame" x="0.0" y="0.0" width="160" height="28"/>
@@ -766,7 +774,7 @@
                                                         </connections>
                                                     </button>
                                                     <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="system" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="s6w-E3-5yE" userLabel="DiskWriteException">
-                                                        <rect key="frame" x="0.0" y="28" width="160" height="28"/>
+                                                        <rect key="frame" x="0.0" y="35" width="160" height="28"/>
                                                         <fontDescription key="fontDescription" type="system" pointSize="13"/>
                                                         <state key="normal" title="DiskWriteException"/>
                                                         <connections>
@@ -774,7 +782,7 @@
                                                         </connections>
                                                     </button>
                                                     <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="system" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="NNd-Ec-zXw">
-                                                        <rect key="frame" x="0.0" y="56" width="160" height="28"/>
+                                                        <rect key="frame" x="0.0" y="70.5" width="160" height="28"/>
                                                         <accessibility key="accessibilityConfiguration" label="crashTheApp"/>
                                                         <fontDescription key="fontDescription" type="system" pointSize="13"/>
                                                         <state key="normal" title="Crash the app"/>
@@ -783,7 +791,7 @@
                                                         </connections>
                                                     </button>
                                                     <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="system" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="wJs-Av-cg2">
-                                                        <rect key="frame" x="0.0" y="84" width="160" height="34.5"/>
+                                                        <rect key="frame" x="0.0" y="105.5" width="160" height="34.5"/>
                                                         <state key="normal" title="Button"/>
                                                         <buttonConfiguration key="configuration" style="plain" title="Use-after-free"/>
                                                         <connections>
@@ -795,7 +803,7 @@
                                         </subviews>
                                     </stackView>
                                     <imageView clipsSubviews="YES" userInteractionEnabled="NO" contentMode="scaleAspectFit" horizontalHuggingPriority="251" verticalHuggingPriority="251" translatesAutoresizingMaskIntoConstraints="NO" id="1zm-ho-TCr">
-                                        <rect key="frame" x="0.0" y="118.5" width="320" height="128"/>
+                                        <rect key="frame" x="0.0" y="140" width="320" height="128"/>
                                         <constraints>
                                             <constraint firstAttribute="height" constant="128" id="lc6-97-p3W"/>
                                         </constraints>
@@ -1170,7 +1178,7 @@
             <color white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
         </systemColor>
         <systemColor name="systemGray5Color">
-            <color red="0.8980392157" green="0.8980392157" blue="0.91764705879999997" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+            <color red="0.89803921568627454" green="0.89803921568627454" blue="0.91764705882352937" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
         </systemColor>
     </resources>
 </document>
diff --git a/Samples/iOS-Swift/iOS-Swift/ErrorsViewController.swift b/Samples/iOS-Swift/iOS-Swift/ErrorsViewController.swift
index 6f31c018e34..c877d01c0ee 100644
--- a/Samples/iOS-Swift/iOS-Swift/ErrorsViewController.swift
+++ b/Samples/iOS-Swift/iOS-Swift/ErrorsViewController.swift
@@ -82,4 +82,20 @@ class ErrorsViewController: UIViewController {
             }
         }
     }
+    
+    @IBAction func corruptEnvelope(_ sender: UIButton) {
+        class TestSentryEnvelopeItem: SentryEnvelopeItem {
+            override var header: SentryEnvelopeItemHeader {
+                SentryEnvelopeItemHeader(type: "test", length: 50)
+            }
+            
+            override var data: Data {
+                defer { exit(0) }
+                return Data(repeating: 1, count: 100_000_000)
+            }
+        }
+        
+        let envelope = SentryEnvelope(id: SentryId(uuid: UUID()), singleItem: TestSentryEnvelopeItem())
+        SentrySDK.capture(envelope)
+    }
 }
diff --git a/Samples/iOS-Swift/iOS-Swift/Tools/SentryCocoaPrivate.h b/Samples/iOS-Swift/iOS-Swift/Tools/SentryCocoaPrivate.h
new file mode 100644
index 00000000000..b93ea309847
--- /dev/null
+++ b/Samples/iOS-Swift/iOS-Swift/Tools/SentryCocoaPrivate.h
@@ -0,0 +1,32 @@
+#import <Foundation/Foundation.h>
+#import <Sentry/Sentry.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface SentryEnvelopeHeader : NSObject
+
+- (instancetype)initWithId:(SentryId *_Nullable)eventId;
+
+@property (nullable, nonatomic, copy) NSDate *sentAt;
+@property (nullable, nonatomic, readonly, copy) SentryId *eventId;
+
+@end
+
+@interface SentryEnvelopeItem : NSObject
+
+- (instancetype)initWithEvent:(SentryEvent *)event;
+
+@property (nonatomic, readonly, strong) SentryEnvelopeItemHeader *header;
+@property (nonatomic, readonly, strong) NSData *data;
+
+@end
+
+@interface SentryEnvelope : NSObject
+
+@property (nonatomic, readonly, strong) SentryEnvelopeHeader *header;
+@property (nonatomic, readonly, strong) NSArray<SentryEnvelopeItem *> *items;
+
+- (instancetype)initWithId:(SentryId *_Nullable)id singleItem:(SentryEnvelopeItem *)item;
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/Samples/iOS-Swift/iOS-Swift/Tools/iOS-Swift-Bridging-Header.h b/Samples/iOS-Swift/iOS-Swift/Tools/iOS-Swift-Bridging-Header.h
index dc79377f45f..f2b27c79954 100644
--- a/Samples/iOS-Swift/iOS-Swift/Tools/iOS-Swift-Bridging-Header.h
+++ b/Samples/iOS-Swift/iOS-Swift/Tools/iOS-Swift-Bridging-Header.h
@@ -1,4 +1,5 @@
 #import "SentryBenchmarking.h"
+#import "SentryCocoaPrivate.h"
 #import "SentryExposure.h"
 #import "SentryUIApplication.h"
 #import <Sentry/PrivateSentrySDKOnly.h>
diff --git a/Samples/iOS-Swift/iOS13-Swift/iOS13-Swift-Bridging-Header.h b/Samples/iOS-Swift/iOS13-Swift/iOS13-Swift-Bridging-Header.h
index 98199b07436..9ada5893584 100644
--- a/Samples/iOS-Swift/iOS13-Swift/iOS13-Swift-Bridging-Header.h
+++ b/Samples/iOS-Swift/iOS13-Swift/iOS13-Swift-Bridging-Header.h
@@ -1,3 +1,5 @@
 #import "SentryBenchmarking.h"
+#import "SentryCocoaPrivate.h"
 #import "SentryUIApplication.h"
 #import <Sentry/PrivateSentrySDKOnly.h>
+#import <Sentry/SentrySDK+Private.h>