diff --git a/modules/seq/base/doc/seq.rst b/modules/seq/base/doc/seq.rst
index 7a849093bc80ecc8921010dab1ee3fe2eaeb0048..243ec0d49108938923169456f4ba9e9cef8a927f 100644
--- a/modules/seq/base/doc/seq.rst
+++ b/modules/seq/base/doc/seq.rst
@@ -322,12 +322,6 @@ an alignment:
     
     Attach the given view to the sequence at index `seq_index`.
     
-    The method now checks for agreement of the one letter code in the structure 
-    and the character in the sequence. If there is a mismatch, AttachView throws 
-    an IntegrityError telling you where in the sequence the problem was 
-    detected. The one letter code of the residue and the character in the 
-    sequence agree, if either one of the is X or they are identical.
-
   .. method:: Cut(start, end)
   
     Removes the columns in the half-closed interval `start`, `end` from the
diff --git a/modules/seq/base/src/impl/sequence_impl.cc b/modules/seq/base/src/impl/sequence_impl.cc
index 15fc8f986db9701832b8267e444bbe14622c534a..a99ea9b6389bcc2655db1bdc459ce6e243253aa7 100644
--- a/modules/seq/base/src/impl/sequence_impl.cc
+++ b/modules/seq/base/src/impl/sequence_impl.cc
@@ -233,26 +233,10 @@ mol::EntityView SequenceImpl::GetAttachedView() const
 
 void SequenceImpl::AttachView(const mol::EntityView& view)
 {
-  static const char* msg_1="Expected 1 chain, but %d chains found";
-  if (view.IsValid() && view.GetChainCount()!=1) {
-    throw IntegrityError(str(format(msg_1) % view.GetChainCount()));
-  }  
+  static const char* msg="Expected 1 chain, but %d chains found";
   attached_view_=view;
-  if (!attached_view_.IsValid()) {
-    return;
-  }
-  for (size_t i=0; i<seq_string_.size(); ++i) {
-    if (mol::ResidueView res=this->GetResidue(i)) {
-      char olc1=res.GetOneLetterCode();
-      char olc2=seq_string_[i];
-      if (olc1!='X' && olc2!='X' && olc1!=olc2) {
-        std::stringstream ss;
-        ss << "One letter code of residue and sequence does not agree "
-              "at position " <<  i << " in sequence (" << res.GetOneLetterCode() 
-              << "!=" << seq_string_[i] << ")";
-        throw IntegrityError(ss.str());
-      }
-    }
+  if (view.IsValid() && attached_view_.GetChainCount()!=1) {
+    throw IntegrityError(str(format(msg) % attached_view_.GetChainCount()));
   }
 }