diff --git a/std/ascii.d b/std/ascii.d
index 07f4a6a00..847466e63 100644
--- a/std/ascii.d
+++ b/std/ascii.d
@@ -146,9 +146,14 @@ enum ControlChar : char
 ///
 @safe pure nothrow @nogc unittest
 {
+    import std.algorithm.comparison, std.algorithm.searching, std.range, std.traits;
+
     // Because all ASCII characters fit in char, so do these
     static assert(ControlChar.ack.sizeof == 1);
 
+    // All control characters except del are in row starting from 0
+    static assert(EnumMembers!ControlChar.only.until(ControlChar.del).equal(iota(32)));
+
     static assert(ControlChar.nul == '\0');
     static assert(ControlChar.bel == '\a');
     static assert(ControlChar.bs  == '\b');