diff --git a/appveyor.yml b/appveyor.yml
index 5b4e9d5529a51a581585114485786092c1f62289..8b794bdeb9ea07a9ba7cf62314e2a55f2bd50281 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -9,18 +9,18 @@ skip_branch_with_pr: true
 
 environment:
   matrix:
-    - QTDIR: C:\Qt\5.13\mingw73_32
+    - QTDIR: C:\Qt\5.15\mingw81_32
       CMAKE_GENERATOR: MinGW Makefiles
-      MINGW_PATH: C:\Qt\Tools\mingw730_32
+      MINGW_PATH: C:\Qt\Tools\mingw810_32
       # https://wiki.qt.io/Qt_5.13_Tools_and_Versions
       # https://www.appveyor.com/docs/windows-images-software/#tools
       OPENSSL_PATH: C:\OpenSSL-v111-Win32\bin
       LIBSSL: libssl-1_1.dll
       LIBCRYPTO: libcrypto-1_1.dll
 
-    - QTDIR: C:\Qt\5.13\mingw73_64
+    - QTDIR: C:\Qt\5.15\mingw81_64
       CMAKE_GENERATOR: MinGW Makefiles
-      MINGW_PATH: C:\Qt\Tools\mingw730_64
+      MINGW_PATH: C:\Qt\Tools\mingw810_64
       OPENSSL_PATH: C:\OpenSSL-v111-Win64\bin
       LIBSSL: libssl-1_1-x64.dll
       LIBCRYPTO: libcrypto-1_1-x64.dll
diff --git a/src/tests/tests.cpp b/src/tests/tests.cpp
index 23ad4dc6ca1318908a616bd73d5c4737bba5bfc8..8e5723bf52dee816e2ad480a82995dea169a6ffb 100644
--- a/src/tests/tests.cpp
+++ b/src/tests/tests.cpp
@@ -189,6 +189,10 @@ bool testStderr(const QByteArray &stderrData, TestInterface::ReadStderrFlag flag
         plain("ERROR: QtCritical: QWindowsPipeWriter::write failed. (The pipe is being closed.)"),
         plain("ERROR: QtCritical: QWindowsPipeWriter: asynchronous write failed. (The pipe has been ended.)"),
 
+        // Windows Qt 5.15.2
+        plain("[qt.qpa.mime] QtWarning: Retrying to obtain clipboard."),
+        plain("[qt.qpa.fonts] QtWarning: Unable to enumerate family ' \"Font Awesome 5 Free Solid (CopyQ)\" '"),
+
         // macOS
         plain("QtWarning: Failed to get QCocoaScreen for NSObject(0x0)"),
         plain("ERROR: Failed to open session mutex: QSystemSemaphore::handle:: ftok failed"),
diff --git a/utils/appveyor/after_build.bat b/utils/appveyor/after_build.bat
index a3d3c9f0163c04051a95043d3adb1c98e699f25e..23b277529685c462a9f35688562df208240208d8 100644
--- a/utils/appveyor/after_build.bat
+++ b/utils/appveyor/after_build.bat
@@ -34,7 +34,6 @@ xcopy /F "%OPENSSL_PATH%\%LIBSSL%" "%Destination%" || goto :error
 %QTDIR%\bin\windeployqt --version
 %QTDIR%\bin\windeployqt --help
 %QTDIR%\bin\windeployqt ^
-  --release ^
   --no-system-d3d-compiler ^
   --no-angle ^
   --no-opengl-sw ^