diff --git a/applications/utilities/mesh/generation/extrude/extrudeMesh/extrudeMesh.C b/applications/utilities/mesh/generation/extrude/extrudeMesh/extrudeMesh.C
index 8f9c0b9d7bb8cfa0dcb446fc317064c43c04e174..f46706141be5ad6e0705d65ee16304d5418590d0 100644
--- a/applications/utilities/mesh/generation/extrude/extrudeMesh/extrudeMesh.C
+++ b/applications/utilities/mesh/generation/extrude/extrudeMesh/extrudeMesh.C
@@ -704,7 +704,7 @@ int main(int argc, char *argv[])
                 regionName,
                 runTimeExtruded.constant(),
                 runTimeExtruded,
-                IOobject::READ_IF_PRESENT,  // Read fv* if present
+                IOobject::NO_READ,  // Do not read primitives, do read fv*
                 IOobject::AUTO_WRITE,
                 false
             ),
diff --git a/src/meshTools/polyTopoChange/polyTopoChange.C b/src/meshTools/polyTopoChange/polyTopoChange.C
index aceb9a9fbf1250e1da78e837ab1d581abcbcb69f..30268d36e39b3a5b868fa7ce97ea2f1387f15706 100644
--- a/src/meshTools/polyTopoChange/polyTopoChange.C
+++ b/src/meshTools/polyTopoChange/polyTopoChange.C
@@ -142,7 +142,11 @@ void Foam::polyTopoChange::countMap
 
         if (oldCelli >= 0)
         {
-            if (reverseMap[oldCelli] == newCelli)
+            if
+            (
+                oldCelli < reverseMap.size()
+             && reverseMap[oldCelli] == newCelli
+            )
             {
                 // unchanged
             }