diff --git a/src/experimental/_impl/_lsystem2_impl.scad b/src/experimental/_impl/_lsystem2_impl.scad
index 1262029d..6fb0dcaf 100644
--- a/src/experimental/_impl/_lsystem2_impl.scad
+++ b/src/experimental/_impl/_lsystem2_impl.scad
@@ -20,7 +20,8 @@ function _next_t2(t, code, angle, leng) =
     is_undef(code) || code == "[" || code == "]" ? t :
     code == "F" || code == "f" ? turtle2d("forward", t, leng) :
     code == "+" ? turtle2d("turn", t, angle) :
-    code == "-" ? turtle2d("turn", t, -angle) : t;    
+    code == "-" ? turtle2d("turn", t, -angle) : 
+    code == "|" ? turtle2d("turn", t, 180) : t;    
 
 // It doesn't use recursion to avoid recursion error.    
 function _lines(t, codes, angle, leng) = 
diff --git a/src/experimental/_impl/_lsystem3_impl.scad b/src/experimental/_impl/_lsystem3_impl.scad
index a0a2c03a..d5d5c080 100644
--- a/src/experimental/_impl/_lsystem3_impl.scad
+++ b/src/experimental/_impl/_lsystem3_impl.scad
@@ -20,7 +20,8 @@ function _next_t2(t, code, angle, leng) =
     is_undef(code) || code == "[" || code == "]" ? t :
     code == "F" || code == "f" ? turtle3d("xu_move", t, leng) :
     code == "+" ? turtle3d("zu_turn", t, angle) :
-    code == "-" ? turtle3d("zu_turn", t, -angle) : t;    
+    code == "-" ? turtle3d("zu_turn", t, -angle) : 
+    code == "|" ? turtle2d("zu_turn", t, 180) : t;       
 
 // It doesn't use recursion to avoid recursion error.    
 function _lines(t, codes, angle, leng) = 
diff --git a/src/experimental/lsystem2.scad b/src/experimental/lsystem2.scad
index 924b3ac6..37265ab0 100644
--- a/src/experimental/lsystem2.scad
+++ b/src/experimental/lsystem2.scad
@@ -7,6 +7,7 @@ use <turtle/turtle2d.scad>;
    f  Move forward without drawing a line
    +  Turn left
    -  Turn right
+   |  Reverse direction (ie: turn by 180 degrees)
    [  Push current turtle state onto stack
    ]  Pop current turtle state from the stack