diff --git a/Intersections_2/include/CGAL/Intersections_2/Segment_2_Segment_2.h b/Intersections_2/include/CGAL/Intersections_2/Segment_2_Segment_2.h
index 9d88487598e..e4eaa4652d5 100644
--- a/Intersections_2/include/CGAL/Intersections_2/Segment_2_Segment_2.h
+++ b/Intersections_2/include/CGAL/Intersections_2/Segment_2_Segment_2.h
@@ -88,8 +88,10 @@ seg_seg_do_intersect_crossing(
           return S2S2_inter_info(i2);
         case RIGHT_TURN:
           return S2S2_inter_info(false);
-        default: // LEFT_TURN
+        case LEFT_TURN:
           return S2S2_inter_info(true);
+        default:
+          CGAL_assume(false);
       }
     }
     case RIGHT_TURN:
@@ -100,14 +102,18 @@ seg_seg_do_intersect_crossing(
           return S2S2_inter_info(i2);
         case RIGHT_TURN:
           return S2S2_inter_info(true);
-        default: // LEFT_TURN
+        case LEFT_TURN:
           return S2S2_inter_info(false);
+        default:
+          CGAL_assume(false);
       }
     }
-    default: //COLLINEAR
+    case COLLINEAR:
       if (extra_test && k.collinear_2_object()(p3,p4,p2))
         return S2S2_inter_info(i3, i2);
       return S2S2_inter_info(i3);
+    default:
+      CGAL_assume(false);
     }
     CGAL_kernel_assertion(false);
     return S2S2_inter_info(false);
@@ -143,8 +149,10 @@ seg_seg_do_intersect_contained(
           return S2S2_inter_info(i4);
         case RIGHT_TURN:
           return S2S2_inter_info(true);
-        default: // LEFT_TURN
+        case LEFT_TURN:
           return S2S2_inter_info(false);
+        default:
+          CGAL_assume(false);
       }
     }
     case RIGHT_TURN:
@@ -155,14 +163,18 @@ seg_seg_do_intersect_contained(
           return S2S2_inter_info(i4);
         case RIGHT_TURN:
           return S2S2_inter_info(false);
-        default: // LEFT_TURN
+        case LEFT_TURN:
           return S2S2_inter_info(true);
+        default:
+          CGAL_assume(false);
       }
     }
-    default: // COLLINEAR
+    case COLLINEAR:
         if (extra_test && k.collinear_2_object()(p3,p4,p2))
           return S2S2_inter_info(i3, i4);
         return S2S2_inter_info(i3);
+    default:
+      CGAL_assume(false);
     }
     CGAL_kernel_assertion(false);
     return S2S2_inter_info(false);
@@ -214,7 +226,7 @@ do_intersect_with_info(const typename K::Segment_2 &seg1,
             return S2S2_inter_info(false);
         case EQUAL:
             return S2S2_inter_info(A2_id); // DI_MORE_INFO_TAG: A2==B1 but only A2 is reported
-        default: // LARGER
+        case LARGER:
             switch(make_certain(compare_xy(A2,B2))) {
             case SMALLER:
                 return seg_seg_do_intersect_crossing(A1,A2,B1,B2, A1_id,A2_id,B1_id+2,B2_id+2, k, extra_test);
@@ -223,9 +235,14 @@ do_intersect_with_info(const typename K::Segment_2 &seg1,
                 if (extra_test && k.collinear_2_object()(A1, A2, B1))
                   return S2S2_inter_info(B1_id+2, B2_id+2); // DI_MORE_INFO_TAG: A2==B2 but only B2 is reported
                 return S2S2_inter_info(A2_id); // DI_MORE_INFO_TAG: A2==B2 but only A2 is reported
-            default: // LARGER
+            case LARGER:
                 return seg_seg_do_intersect_contained(A1,A2,B1,B2, A1_id,A2_id,B1_id+2,B2_id+2, k, extra_test);
+            default:
+              CGAL_assume(false);
             }
+        default:
+          CGAL_assume(false);
+
         }
     case EQUAL:
         if (extra_test)
@@ -239,20 +256,23 @@ do_intersect_with_info(const typename K::Segment_2 &seg1,
           case EQUAL:
             // A1 = B1 < A2 = B2
             return S2S2_inter_info(A1_id, A2_id); // DI_MORE_INFO_TAG: A1==B1 and A2==B2 but only A1 and A2 are reported
-          default: // LARGER
+          case LARGER:
             // A1 = B1 < B2 < A2
             if (k.collinear_2_object()(A1,A2,B2))
               return S2S2_inter_info(B1_id+2, B2_id+2); // DI_MORE_INFO_TAG: A1==B1 but only B1 is reported
+          break;
+          default:
+            CGAL_assume(false);
           }
         }
         return S2S2_inter_info(A1_id); // DI_MORE_INFO_TAG: A1==B1 but only A1 is reported
-    default: // LARGER
+    case LARGER:
         switch(make_certain(compare_xy(B2,A1))) {
         case SMALLER:
             return S2S2_inter_info(false);
         case EQUAL:
             return S2S2_inter_info(A1_id); // DI_MORE_INFO_TAG: A1==B2 but only A1 is reported
-        default: // LARGER
+        case LARGER:
             switch(make_certain(compare_xy(B2,A2))) {
             case SMALLER:
                 return seg_seg_do_intersect_crossing(B1,B2,A1,A2, B1_id+2,B2_id+2,A1_id,A2_id, k, extra_test);
@@ -261,10 +281,16 @@ do_intersect_with_info(const typename K::Segment_2 &seg1,
                 if (extra_test && k.collinear_2_object()(B1, A1, B2))
                   return S2S2_inter_info(A1_id, A2_id); // DI_MORE_INFO_TAG: A2==B2 but only A2 is reported
                 return S2S2_inter_info(A2_id); // DI_MORE_INFO_TAG: A2==B2 but only A2 is reported
-            default: // LARGER
+            case LARGER:
                 return seg_seg_do_intersect_contained(B1,B2,A1,A2, B1_id+2,B2_id+2,A1_id,A2_id, k, extra_test);
+            default:
+              CGAL_assume(false);
             }
+        default:
+          CGAL_assume(false);
         }
+    default:
+      CGAL_assume(false);
     }
 
     CGAL_kernel_assertion(false);