diff --git a/src/lagrangian/basic/Cloud/CloudIO.C b/src/lagrangian/basic/Cloud/CloudIO.C
index cbca096a16..ea37ea27a9 100644
--- a/src/lagrangian/basic/Cloud/CloudIO.C
+++ b/src/lagrangian/basic/Cloud/CloudIO.C
@@ -46,6 +46,13 @@ void Foam::Cloud<ParticleType>::initCloud(const bool checkClass)
             readFields();
         }
     }
+    else
+    {
+        WarningIn("Cloud<ParticleType>::initCloud(const bool checkClass)")
+            << "Cannot read particle positions file " << nl
+            << "    " << ioP.path() << nl
+            << "    assuming the initial cloud contains 0 particles." << endl;
+    }
 }