diff --git a/lists.scad b/lists.scad
index f8be75a..d28547f 100644
--- a/lists.scad
+++ b/lists.scad
@@ -9,6 +9,10 @@
 // FileFootnotes: STD=Included in std.scad
 //////////////////////////////////////////////////////////////////////
 
+_BOSL2_LISTS = is_undef(_BOSL2_STD) && (is_undef(BOSL2_NO_STD_WARNING) || !BOSL2_NO_STD_WARNING) ?
+       echo("Warning: lists.scad included without std.scad; dependencies may be missing\nSet BOSL2_NO_STD_WARNING = true to mute this warning.") true : true;
+
+
 // Terminology:
 //   **List** = An ordered collection of zero or more arbitrary items.  ie: `["a", "b", "c"]`, or `[3, "a", [4,5]]`
 //   **Vector** = A list of numbers. ie: `[4, 5, 6]`