diff --git a/appveyor.yml b/appveyor.yml
index a9e0fc15..3380730e 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -6,10 +6,10 @@ environment:
     TESTING: Func
   - CONFIGURATION: Release
     TESTING: Func
-  - CONFIGURATION: Release
-    TESTING: Avast
-  - CONFIGURATION: Release
-    TESTING: Perf
+  #- CONFIGURATION: Release
+  #  TESTING: Avast
+  #- CONFIGURATION: Release
+  #  TESTING: Perf
 
 install:
 - git submodule update --init --recursive
@@ -32,6 +32,7 @@ test_script:
 - if %TESTING%==Func tools\run-tests.bat %CONFIGURATION%
 - if %TESTING%==Func tools\run-tests.bat %CONFIGURATION% ifstest
 - if %TESTING%==Func tools\run-tests.bat %CONFIGURATION% sample
+- if %TESTING%==Func tools\run-tests.bat %CONFIGURATION% compat
 - if %TESTING%==Avast choco install avastfreeantivirus && fltmc instances -v "C:"
 - if %TESTING%==Avast tools\run-tests.bat %CONFIGURATION% avast-tests
 - if %TESTING%==Perf tools\run-perf-tests.bat %CONFIGURATION% baseline > perf-tests.csv && type perf-tests.csv & appveyor PushArtifact perf-tests.csv
diff --git a/tools/run-tests.bat b/tools/run-tests.bat
index 0a1a3fc6..a061eb98 100755
--- a/tools/run-tests.bat
+++ b/tools/run-tests.bat
@@ -80,6 +80,8 @@ set opt_tests=^
     sample-passthrough-fuse-x86 ^
     sample-fsx-passthrough-fuse-x86 ^
     sample-passthrough-dotnet ^
+    compat-v1.1-passthrough-fuse-x64 ^
+    compat-v1.1-passthrough-fuse-x86 ^
     avast-tests-x64 ^
     avast-tests-x86 ^
     avast-tests-dotnet
@@ -757,6 +759,42 @@ call "%ProjRoot%\tools\fsreg" -u %1
 rmdir /s/q "%TMP%\%1"
 exit /b !RunSampleTestExit!
 
+:compat-v1.1-passthrough-fuse-x64
+call :__run_compat_fuse_test passthrough-fuse v1.1\passthrough-fuse\passthrough-fuse-x64 winfsp-tests-x64
+if !ERRORLEVEL! neq 0 goto fail
+exit /b 0
+
+:compat-v1.1-passthrough-fuse-x86
+call :__run_compat_fuse_test passthrough-fuse v1.1\passthrough-fuse\passthrough-fuse-x86 winfsp-tests-x86
+if !ERRORLEVEL! neq 0 goto fail
+exit /b 0
+
+:__run_compat_fuse_test
+set RunSampleTestExit=0
+mkdir "%TMP%\%1\test"
+call "%ProjRoot%\tools\fsreg" %1 "%ProjRoot%\tst\compat\%2.exe" ^
+    "-ouid=11,gid=65792 --VolumePrefix=%%%%1 %%%%2" "D:P(A;;RPWPLC;;;WD)"
+echo net use L: "\\%1\%TMP::=$%\%1\test"
+net use L: "\\%1\%TMP::=$%\%1\test"
+if !ERRORLEVEL! neq 0 goto fail
+echo net use ^| findstr L:
+net use | findstr L:
+pushd >nul
+cd L: >nul 2>nul || (echo Unable to find drive L: >&2 & goto fail)
+L:
+"%ProjRoot%\build\VStudio\build\%Configuration%\%3.exe" ^
+    --external --resilient --case-insensitive-cmp --share-prefix="\%1\%TMP::=$%\%1\test" ^
+    -create_allocation_test -create_notraverse_test -create_backup_test -create_restore_test -create_namelen_test ^
+    -getfileinfo_name_test -setfileinfo_test -delete_access_test -delete_mmap_test -rename_flipflop_test -rename_mmap_test -setsecurity_test -exec_rename_dir_test ^
+    -reparse* -stream*
+if !ERRORLEVEL! neq 0 set RunSampleTestExit=1
+popd
+echo net use L: /delete
+net use L: /delete
+call "%ProjRoot%\tools\fsreg" -u %1
+rmdir /s/q "%TMP%\%1"
+exit /b !RunSampleTestExit!
+
 :avast-tests-x64
 call :winfsp-tests-x64-external
 if !ERRORLEVEL! neq 0 goto fail
diff --git a/tst/compat/v1.1/passthrough-fuse/README.md b/tst/compat/v1.1/passthrough-fuse/README.md
new file mode 100644
index 00000000..01ad2342
--- /dev/null
+++ b/tst/compat/v1.1/passthrough-fuse/README.md
@@ -0,0 +1,3 @@
+This directory contains binaries of `passthrough-fuse` from release `v1.2B2`. Both `x64` and `x86` binaries are provided.
+
+The WinFsp-FUSE layer added support for `struct fuse_stat_ex` in `v1.2B3` which was a potentially breaking change for backwards compatibility. These binaries are used to verify that WinFsp-FUSE remains backwards compatible.
diff --git a/tst/compat/v1.1/passthrough-fuse/passthrough-fuse-x64.exe b/tst/compat/v1.1/passthrough-fuse/passthrough-fuse-x64.exe
new file mode 100644
index 00000000..a8aad0c6
Binary files /dev/null and b/tst/compat/v1.1/passthrough-fuse/passthrough-fuse-x64.exe differ
diff --git a/tst/compat/v1.1/passthrough-fuse/passthrough-fuse-x86.exe b/tst/compat/v1.1/passthrough-fuse/passthrough-fuse-x86.exe
new file mode 100644
index 00000000..b3aa3a1f
Binary files /dev/null and b/tst/compat/v1.1/passthrough-fuse/passthrough-fuse-x86.exe differ