diff --git a/VERSION b/VERSION
index 4c6e14dd..0ba50bd8 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-8.3.352
+8.3.353
diff --git a/calma/CalmaRdcl.c b/calma/CalmaRdcl.c
index cfc527fd..38814823 100644
--- a/calma/CalmaRdcl.c
+++ b/calma/CalmaRdcl.c
@@ -287,6 +287,13 @@ calmaExact()
  * in fact can be much faster than reading the polygons
  * directly into the cell from GDS.
  *
+ * Return value:
+ *	Return 0 to keep the search going
+ *
+ * Side effects:
+ *	Polygons are copied from use->cu_def to parent.
+ *	use->cu_def is deleted.
+ *
  * ----------------------------------------------------------------------------
  */
 
@@ -298,6 +305,7 @@ calmaFlattenPolygonFunc(use, parent)
     int i;
     CellUse dummy;
     SearchContext scx;
+    HashEntry *he;
 
     if (use->cu_def == NULL || use->cu_def->cd_name == NULL) return 0;
     if (strncmp(use->cu_def->cd_name, "polygon", 7)) return 0;
@@ -310,12 +318,14 @@ calmaFlattenPolygonFunc(use, parent)
     scx.scx_trans = GeoIdentityTransform;
     DBCellCopyAllPaint(&scx, &DBAllButSpaceAndDRCBits, 0, &dummy);
     DBDeleteCellNoModify(use);
+    HashRemove(&CifCellTable, use->cu_def->cd_name);
+    /* There should only be one use, so it can just be cleared */
+    use->cu_def->cd_parents = (CellUse *)NULL;
     DBCellDeleteDef(use->cu_def);
 
     return 0;	/* Keep the search going */
 }
 
-
 /*
  * ----------------------------------------------------------------------------
  *
@@ -347,6 +357,7 @@ calmaParseStructure(filename)
     int timestampval = 0;
     int suffix;
     int mfactor;
+    int locPolygonCount;
     OFFTYPE filepos;
     bool was_called;
     bool was_initialized;
@@ -354,6 +365,8 @@ calmaParseStructure(filename)
     bool do_flatten;
     CellDef *def;
 
+    locPolygonCount = CalmaPolygonCount;
+
     /* Make sure this is a structure; if not, let the caller know we're done */
     PEEKRH(nbytes, rtype);
     if (nbytes <= 0 || rtype != CALMA_BGNSTR)
@@ -587,11 +600,8 @@ calmaParseStructure(filename)
 	CIFPaintCurrent(FILE_CALMA);
     }
 
-    if ((!CalmaSubcellPolygons) && (CalmaPolygonCount > 0))
-    {
+    if ((!CalmaSubcellPolygons) && (locPolygonCount < CalmaPolygonCount))
 	DBCellEnum(cifReadCellDef, calmaFlattenPolygonFunc, (ClientData)cifReadCellDef);
-	CalmaPolygonCount = 0;
-    }
 
     DBAdjustLabelsNew(cifReadCellDef, &TiPlaneRect,
 	      (cifCurReadStyle->crs_flags & CRF_NO_RECONNECT_LABELS) ? 1 : 0);
diff --git a/commands/CmdFI.c b/commands/CmdFI.c
index b362c395..1f318501 100644
--- a/commands/CmdFI.c
+++ b/commands/CmdFI.c
@@ -1959,7 +1959,7 @@ CmdFlatten(w, cmd)
     TxCommand *cmd;
 {
      int		rval, xMask;
-     bool		dolabels, dobox, toplabels, invert, doports;
+     bool		dolabels, dobox, toplabels, invert, doports, doinplace;
      char		*destname;
      CellDef		*newdef;
      CellUse		*newuse;
@@ -1972,6 +1972,7 @@ CmdFlatten(w, cmd)
     toplabels = FALSE;
     dobox = FALSE;
     doports = TRUE;
+    doinplace = FALSE;
 
     rval = 0;
     if (cmd->tx_argc > 2)
@@ -2000,6 +2001,9 @@ CmdFlatten(w, cmd)
 		    case 'b':
 			dobox = (invert) ? FALSE : TRUE;
 			break;
+		    case 'i':
+			doinplace = (invert) ? FALSE : TRUE;
+			break;
 		    case 'l':
 			dolabels = (invert) ? FALSE : TRUE;
 			break;
@@ -2020,7 +2024,8 @@ CmdFlatten(w, cmd)
 			break;
 		    default:
 			TxError("options are: -nolabels, -nosubcircuits, -noports, "
-				"-novendor, -dotoplabels, -doproperty, -dobox\n");
+				"-novendor, -dotoplabels, -doproperty, -dobox, "
+				"-doinplace\n");
 			break;
 		}
 	    }
@@ -2034,6 +2039,51 @@ CmdFlatten(w, cmd)
      	TxError("usage: flatten [-<option>...] destcell\n");
 	return;
     }
+
+    /* Flatten-in-place:  destname is an instance, not a cell def */
+    if (doinplace)
+    {
+	HashEntry *he;
+
+	if (EditCellUse == NULL)
+	{
+	    TxError("The cell def is not editable.\n");
+	    return;
+	}
+
+	he = HashLookOnly(&EditCellUse->cu_def->cd_idHash, destname);
+	if (he == NULL)
+	{
+	    TxError("No cell use %s found in edit cell.\n", destname);
+	    return;
+	}
+	scx.scx_use = (CellUse *)HashGetValue(he);
+	scx.scx_trans = GeoIdentityTransform;
+	scx.scx_area = scx.scx_use->cu_def->cd_bbox;
+
+	UndoDisable();
+
+	DBCellCopyAllPaint(&scx, &DBAllButSpaceAndDRCBits, xMask, EditCellUse);
+	if (dolabels)
+	    FlatCopyAllLabels(&scx, &DBAllTypeBits, xMask, EditCellUse);
+	else if (toplabels)
+	{
+	    int savemask = scx.scx_use->cu_expandMask;
+	    scx.scx_use->cu_expandMask = CU_DESCEND_SPECIAL;
+	    DBCellCopyAllLabels(&scx, &DBAllTypeBits, CU_DESCEND_SPECIAL, EditCellUse);
+	    scx.scx_use->cu_expandMask = savemask;
+	}
+
+	if (xMask != CU_DESCEND_ALL)
+	    DBCellCopyAllCells(&scx, xMask, EditCellUse, (Rect *)NULL);
+
+	/* Remove the use */
+	DBDeleteCell(scx.scx_use);
+
+	UndoEnable();
+	return;
+    }
+
     /* create the new def */
     newdef = DBCellLookDef(destname);
     if ((newdef != NULL) && (dobox == FALSE))
diff --git a/doc/html/flatten.html b/doc/html/flatten.html
index 6cd5639e..4139d31b 100644
--- a/doc/html/flatten.html
+++ b/doc/html/flatten.html
@@ -71,6 +71,12 @@ Flatten edit cell into the indicated destination cell.
         <DT> <B>-dobox</B>
 	<DD> When this option is specified, magic flattens only the area
 	     of the circuit that is inside the boundary of the cursor box.
+        <DT> <B>-doinplace</B>
+	<DD> When this option is specified, <I>cellname</I> must be the
+	     name of a cell <I>use</I> (instance), not a cell <I>definition</I>.
+	     The cell use <I>cellname</I> is assumed to exist in the current
+	     edit cell.  The cell use will be removed from the edit cell and
+	     replaced with its flattened contents.
       </DL>
 
       Note that <I>cellname</I> is a top-level cell but is not displayed