diff --git a/src/StdMeshers/StdMeshers_Prism_3D.cxx b/src/StdMeshers/StdMeshers_Prism_3D.cxx
index 8998a2949..cf6e448b7 100644
--- a/src/StdMeshers/StdMeshers_Prism_3D.cxx
+++ b/src/StdMeshers/StdMeshers_Prism_3D.cxx
@@ -1334,10 +1334,14 @@ bool StdMeshers_PrismAsBlock::Init(SMESH_MesherHelper* helper,
   {
     list< TopoDS_Face >::iterator faceIt = wallFaces.begin();
     for ( ; faceIt != wallFaces.end(); ++faceIt )
-      for (TopExp_Explorer edge(*faceIt, TopAbs_EDGE); edge.More(); edge.Next()) {
-        if ( !helper->IsSubShape( edge.Current(), topSM->GetSubShape() ))
-          return error(COMPERR_BAD_SHAPE);
-      }
+    {
+      bool hasCommon = false;
+      for (TopExp_Explorer edge(*faceIt, TopAbs_EDGE); !hasCommon && edge.More(); edge.Next())
+        if ( helper->IsSubShape( edge.Current(), topSM->GetSubShape() ))
+          hasCommon = true;
+      if ( !hasCommon )
+        return error(COMPERR_BAD_SHAPE);
+    }
   }
 
   // Find columns of wall nodes and calculate edges' lengths