diff --git a/pom.xml b/pom.xml
index d190b3b67a..c7914c2c48 100644
--- a/pom.xml
+++ b/pom.xml
@@ -524,6 +524,11 @@
         <artifactId>buildnumber-maven-plugin</artifactId>
         <!-- Warning! 3.2.1 caused issues during verification, 3.2.0 is known to work correctly. -->
         <version>3.2.0</version>
+        <configuration>
+          <!-- Source distributions carry no .git metadata, so the revision cannot be read.
+               Record an explicit value instead of leaving ${buildNumber} unresolved. -->
+          <revisionOnScmFailure>unknown</revisionOnScmFailure>
+        </configuration>
         <executions>
           <execution>
             <phase>validate</phase>