diff --git a/main/core/src/main/java/org/cryptomator/webdav/jackrabbit/EncryptedFilePart.java b/main/core/src/main/java/org/cryptomator/webdav/jackrabbit/EncryptedFilePart.java
index b9d241799..e9af363b7 100644
--- a/main/core/src/main/java/org/cryptomator/webdav/jackrabbit/EncryptedFilePart.java
+++ b/main/core/src/main/java/org/cryptomator/webdav/jackrabbit/EncryptedFilePart.java
@@ -53,7 +53,7 @@ class EncryptedFilePart extends EncryptedFile {
 		assert Files.isRegularFile(filePath);
 		assert contentLength != null;
 
-		final Long rangeLength = range.getRight() - range.getLeft();
+		final Long rangeLength = range.getRight() - range.getLeft() + 1;
 		outputContext.setModificationTime(Files.getLastModifiedTime(filePath).toMillis());
 		if (rangeLength <= 0 || range.getLeft() > contentLength - 1) {
 			// unsatisfiable content range:
diff --git a/main/crypto-aes/src/main/java/org/cryptomator/crypto/aes256/Aes256Cryptor.java b/main/crypto-aes/src/main/java/org/cryptomator/crypto/aes256/Aes256Cryptor.java
index 838e25801..0d3cbb86d 100644
--- a/main/crypto-aes/src/main/java/org/cryptomator/crypto/aes256/Aes256Cryptor.java
+++ b/main/crypto-aes/src/main/java/org/cryptomator/crypto/aes256/Aes256Cryptor.java
@@ -549,7 +549,7 @@ public class Aes256Cryptor implements Cryptor, AesCryptographicConfiguration {
 		final Long fileSize = sensitiveHeaderContentBuf.getLong();
 		sensitiveHeaderContentBuf.get(fileKeyBytes);
 
-		assert pos + length < fileSize;
+		assert pos + length - 1 < fileSize;
 
 		// find first relevant block:
 		final long startBlock = pos / CONTENT_MAC_BLOCK; // floor