diff --git a/src/it/check-buildplan-ok/invoker.properties b/src/it/check-buildplan-ok/invoker.properties
index f2191ac..e3de0b3 100644
--- a/src/it/check-buildplan-ok/invoker.properties
+++ b/src/it/check-buildplan-ok/invoker.properties
@@ -15,4 +15,4 @@
 # specific language governing permissions and limitations
 # under the License.
 
-invoker.goals=artifact:check-buildplan
+invoker.goals=artifact:check-buildplan -Ddiagnose
diff --git a/src/it/check-buildplan-ok/pom.xml b/src/it/check-buildplan-ok/pom.xml
index 01a0ac3..9ea0566 100644
--- a/src/it/check-buildplan-ok/pom.xml
+++ b/src/it/check-buildplan-ok/pom.xml
@@ -26,7 +26,7 @@
   <packaging>pom</packaging>
 
   <properties>
-    <project.build.outputTimestamp>2011-11-11T11:11:11Z</project.build.outputTimestamp>
+    <project.build.outputTimestamp>0</project.build.outputTimestamp>
   </properties>
 
   <modules>
diff --git a/src/main/java/org/apache/maven/plugins/artifact/buildinfo/AbstractBuildinfoMojo.java b/src/main/java/org/apache/maven/plugins/artifact/buildinfo/AbstractBuildinfoMojo.java
index 5977cbb..3dc6b6f 100644
--- a/src/main/java/org/apache/maven/plugins/artifact/buildinfo/AbstractBuildinfoMojo.java
+++ b/src/main/java/org/apache/maven/plugins/artifact/buildinfo/AbstractBuildinfoMojo.java
@@ -172,10 +172,11 @@ static boolean hasBadOutputTimestamp(
             boolean diagnose) {
         Instant timestamp =
                 MavenArchiver.parseBuildOutputTimestamp(outputTimestamp).orElse(null);
+        String effective = ((timestamp == null) ? "disabled" : DateTimeFormatter.ISO_INSTANT.format(timestamp));
 
         if (diagnose) {
-            log.info("outputTimestamp = " + outputTimestamp + " => "
-                    + ((timestamp == null) ? "disabled" : DateTimeFormatter.ISO_INSTANT.format(timestamp)));
+            log.info("outputTimestamp = " + outputTimestamp
+                    + (effective.equals(outputTimestamp) ? "" : (" => " + effective)));
 
             String projectProperty = project.getProperties().getProperty("project.build.outputTimestamp");
             String modelProperty = project.getModel().getProperties().getProperty("project.build.outputTimestamp");
@@ -185,11 +186,29 @@ static boolean hasBadOutputTimestamp(
             log.info("plugin outputTimestamp parameter diagnostics:" + System.lineSeparator()
                     + "        - plugin outputTimestamp parameter (defaultValue=\"${project.build.outputTimestamp}\") = "
                     + outputTimestamp + System.lineSeparator()
-                    + "        - project project.build.outputTimestamp property = " + projectProperty
+                    + "        - project.build.outputTimestamp property from project = " + projectProperty
                     + System.lineSeparator()
-                    + "        - model project.build.outputTimestamp property = " + modelProperty
+                    + "        - project.build.outputTimestamp property from project model = " + modelProperty
                     + System.lineSeparator()
-                    + "        - original model project.build.outputTimestamp property = " + originalModelProperty);
+                    + "        - project.build.outputTimestamp property from project original model = "
+                    + originalModelProperty);
+
+            MavenProject parent = project.getParent();
+            if (parent != null) {
+                StringBuilder sb = new StringBuilder("Inheritance analysis property:" + System.lineSeparator()
+                        + "        - current " + project.getId() + " property = " + projectProperty);
+                while (parent != null) {
+                    String parentProperty = parent.getProperties().getProperty("project.build.outputTimestamp");
+                    sb.append(System.lineSeparator());
+                    sb.append("        - parent " + (reactorProjects.contains(parent) ? "in reactor " : "")
+                            + parent.getId() + " property = " + parentProperty);
+                    if (!projectProperty.equals(parentProperty)) {
+                        break;
+                    }
+                    parent = parent.getParent();
+                }
+                log.info(sb.toString());
+            }
         }
 
         if (timestamp == null) {
@@ -209,7 +228,7 @@ static boolean hasBadOutputTimestamp(
 
         if (log.isDebugEnabled()) {
             log.debug("project.build.outputTimestamp = \"" + outputTimestamp + "\" => "
-                    + DateTimeFormatter.ISO_INSTANT.format(timestamp));
+                    + (effective.equals(outputTimestamp) ? "" : (" => " + effective)));
         }
 
         // check if timestamp defined in a project from reactor: warn if it is not the case