diff --git a/owlps-positioner/src/csvstringreader.cc b/owlps-positioner/src/csvstringreader.cc
index b4377ae..b6b18f8 100644
--- a/owlps-positioner/src/csvstringreader.cc
+++ b/owlps-positioner/src/csvstringreader.cc
@@ -132,6 +132,10 @@ bool CSVStringReader::read_timestamp(Timestamp &t)
 }
 
 
+/**
+ * The first field (X) can start with an opening parenthesis, and the
+ * last one (Z) can finish with a closing parenthesis.
+ */
 bool CSVStringReader::read_point3d(Point3D &p)
 {
   float coord[3] ;
@@ -142,9 +146,19 @@ bool CSVStringReader::read_point3d(Point3D &p)
         return false ;
       ++current_field_nb ;
 
+      string field = *token_iterator ;
+      if (field.empty())
+        return false ;
+
+      /* Handle a leading '(' and a trailing ')' */
+      if (i == 0 && field.front() == '(')
+        field.erase(field.begin()) ;
+      if (i == 2 && field.back() == ')')
+        field.pop_back() ;
+
       try
         {
-          coord[i] = lexical_cast<float>(*token_iterator) ;
+          coord[i] = lexical_cast<float>(field) ;
         }
       catch (bad_lexical_cast &e)
         {