diff --git a/src/entity-py.cc b/src/entity-py.cc
index 86255cc1d9b7ae68dcafe50bad6489e07f2daa69..5efb5ada89f34dc295fe5debeb889358e0630bd6 100644
--- a/src/entity-py.cc
+++ b/src/entity-py.cc
@@ -280,8 +280,8 @@ namespace dynamicgraph {
 	    if (!PyTuple_Check(row)) {
 	      throw ExceptionFactory(ExceptionFactory::GENERIC,
 				     "matrix");
-	      fillMatrixRow(m, iRow, row);
 	    }
+	    fillMatrixRow(m, iRow, row);
 	  }
 	  return Value(m);
 	  break;