diff --git a/Modules/CommonsLib/Sources/CommonsLib/Constants.swift b/Modules/CommonsLib/Sources/CommonsLib/Constants.swift
index a00544ab..4257dcfc 100644
--- a/Modules/CommonsLib/Sources/CommonsLib/Constants.swift
+++ b/Modules/CommonsLib/Sources/CommonsLib/Constants.swift
@@ -84,8 +84,8 @@ public struct Constants {
     }
 
     public struct File {
-        public static let LibDigidocLog = "libdigidocpp.log"
-        public static let AppLog = "ria_digidoc.log"
+        public static let LibDigidocLog = "libdigidocpp.txt"
+        public static let AppLog = "ria_digidoc.txt"
         public static let LDAPCertsPem = "ldapCerts.pem"
         public static let nfcCANKey = "canKey.txt"
     }
diff --git a/Modules/UtilsLib/Tests/UtilsLibTests/File/DirectoriesTests.swift b/Modules/UtilsLib/Tests/UtilsLibTests/File/DirectoriesTests.swift
index 4c07efe7..0a14b7f6 100644
--- a/Modules/UtilsLib/Tests/UtilsLibTests/File/DirectoriesTests.swift
+++ b/Modules/UtilsLib/Tests/UtilsLibTests/File/DirectoriesTests.swift
@@ -238,7 +238,7 @@ struct DirectoriesTests {
 
         #expect(logFilePath != nil)
         #expect(trimmedExpectedDirectoryPath == trimmedLogFilePath)
-        #expect("libdigidocpp.log" == logFilePath?.lastPathComponent)
+        #expect("libdigidocpp.txt" == logFilePath?.lastPathComponent)
     }
 
     @Test
@@ -249,7 +249,7 @@ struct DirectoriesTests {
         let logFilePath = try Directories.getLibdigidocLogFile(from: nil, fileManager: mockFileManager)
 
         #expect(logFilePath != nil)
-        #expect("libdigidocpp.log" == logFilePath?.lastPathComponent)
+        #expect("libdigidocpp.txt" == logFilePath?.lastPathComponent)
     }
 
     @Test
diff --git a/RIADigiDoc/ViewModel/DiagnosticsViewModel.swift b/RIADigiDoc/ViewModel/DiagnosticsViewModel.swift
index 1badf300..6ad4122b 100644
--- a/RIADigiDoc/ViewModel/DiagnosticsViewModel.swift
+++ b/RIADigiDoc/ViewModel/DiagnosticsViewModel.swift
@@ -250,7 +250,7 @@ class DiagnosticsViewModel: DiagnosticsViewModelProtocol, Loggable {
 
     func createDiagnosticsFile(languageSettings: LanguageSettingsProtocol, directory: URL? = nil) async -> URL? {
         let diagnosticsText = buildDiagnosticsText(languageSettings: languageSettings)
-        let diagnosticsFileName = "ria_digidoc_\(self.versionSectionContent)_diagnostics.log"
+        let diagnosticsFileName = "ria_digidoc_\(self.versionSectionContent)_diagnostics.txt"
 
         return await writeTempFile(fileName: diagnosticsFileName, directory: directory) { fileURL in
             try await logCollector.write(diagnosticsText, to: fileURL)
@@ -363,7 +363,7 @@ class DiagnosticsViewModel: DiagnosticsViewModelProtocol, Loggable {
     }
 
     public func createLogFile(directory: URL? = nil) async -> URL? {
-        let logFileName = "ria_digidoc_\(self.versionSectionContent).log"
+        let logFileName = "ria_digidoc_\(self.versionSectionContent).txt"
 
         return await writeTempFile(fileName: logFileName, directory: directory) { fileURL in
             try await logCollector.writeLogFile(
diff --git a/RIADigiDocTests/ViewModel/DiagnosticsViewModelTests.swift b/RIADigiDocTests/ViewModel/DiagnosticsViewModelTests.swift
index adaffac6..c506eeb0 100644
--- a/RIADigiDocTests/ViewModel/DiagnosticsViewModelTests.swift
+++ b/RIADigiDocTests/ViewModel/DiagnosticsViewModelTests.swift
@@ -305,6 +305,7 @@ final class DiagnosticsViewModelTests {
 
         let fileUrl = try #require(diagnosticsFileUrl)
         #expect(!fileUrl.resolvedPath.isEmpty)
+        #expect(fileUrl.pathExtension == "txt")
         #expect(FileManager.default.fileExists(atPath: fileUrl.resolvedPath))
     }
 
@@ -457,6 +458,7 @@ final class DiagnosticsViewModelTests {
 
         let fileUrl = try #require(logFileUrl)
         #expect(!fileUrl.resolvedPath.isEmpty)
+        #expect(fileUrl.pathExtension == "txt")
 
         let contents = try String(contentsOf: fileUrl, encoding: .utf8)
         #expect(contents.contains("===== File: \(CommonsLib.Constants.File.LibDigidocLog) ====="))