diff --git a/testframework/build.gradle b/testframework/build.gradle
index 77a836be65..0caa8fd3f6 100644
--- a/testframework/build.gradle
+++ b/testframework/build.gradle
@@ -36,5 +36,14 @@ spotless {
         toggleOffOn()
         eclipse().configFile rootProject.file('codeformat/formatter-config.xml')
         importOrder()
+
+        // courtesy of diffplug/spotless#240
+        // https://github.com/diffplug/spotless/issues/240#issuecomment-385206606
+        custom 'noWildcardImports', { String fileContents ->
+            if (fileContents.contains('*;\n')) {
+                throw new GradleException('No wildcard imports are allowed!')
+            }
+        }
+        bumpThisNumberIfACustomStepChanges(1)
     }
-}
\ No newline at end of file
+}
diff --git a/tests/build.gradle b/tests/build.gradle
index f9c6dcec1e..3ae4763568 100644
--- a/tests/build.gradle
+++ b/tests/build.gradle
@@ -113,5 +113,14 @@ spotless {
         toggleOffOn()
         eclipse().configFile rootProject.file('codeformat/formatter-config.xml')
         importOrder()
+
+        // courtesy of diffplug/spotless#240
+        // https://github.com/diffplug/spotless/issues/240#issuecomment-385206606
+        custom 'noWildcardImports', { String fileContents ->
+            if (fileContents.contains('*;\n')) {
+                throw new GradleException('No wildcard imports are allowed!')
+            }
+        }
+        bumpThisNumberIfACustomStepChanges(1)
     }
 }