diff --git a/.appveyor.yml b/.appveyor.yml
index c1e05ae..0c12b8a 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -48,6 +48,9 @@ skip_commits:
 #   build matrix configuration    #
 #---------------------------------#
 
+# Default build worker image
+image: Visual Studio 2015
+
 # Build Configurations: dll/static, regular/debug
 configuration:
   - dynamic
diff --git a/appveyor/.appveyor.yml.example-full b/appveyor/.appveyor.yml.example-full
index 318e30a..d46500c 100644
--- a/appveyor/.appveyor.yml.example-full
+++ b/appveyor/.appveyor.yml.example-full
@@ -51,6 +51,9 @@ skip_commits:
 # are executed sequentially, each one taking 10-15 minutes.
 # Consider this when defining your build matrix. (A full matrix build takes more than 8 hours.)
 
+# Default build worker image
+image: Visual Studio 2015
+
 # Build Configurations: dll/static, regular/debug
 configuration:
   - dynamic
diff --git a/appveyor/.appveyor.yml.example-mini b/appveyor/.appveyor.yml.example-mini
index 024c84a..edbb65a 100644
--- a/appveyor/.appveyor.yml.example-mini
+++ b/appveyor/.appveyor.yml.example-mini
@@ -19,6 +19,8 @@ skip_commits:
     - '**/*.md'
     - '.travis.yml'
 
+image: Visual Studio 2019
+
 # Build Configurations: dll/static, regular/debug
 configuration:
   - dynamic
@@ -33,10 +35,8 @@ environment:
   matrix:
   - CMP: vs2019
     BASE: 7.0
-    APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
   - CMP: vs2019
     BASE: 3.15
-    APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
 
 # Platform: processor architecture
 platform:
diff --git a/appveyor/README.md b/appveyor/README.md
index 73e9648..108b293 100644
--- a/appveyor/README.md
+++ b/appveyor/README.md
@@ -53,3 +53,16 @@
 
  6. Push your changes and check
     [ci.appveyor.com](https://ci.appveyor.com/) for your build results.
+
+## Known Issues
+
+#### Build Worker Images
+The AppVeyor documentation on build worker images doesn't seem to fully
+describe the way things are handled internally.
+
+The tested and suggested reproducible way of defining the build worker image
+is shown in the example configuration files:
+
+ - Set the default image using the `image:` tag.
+ - Override the image for specific jobs by setting the
+   `APPVEYOR_BUILD_WORKER_IMAGE` environment variable.