diff --git a/build/Makefile.in b/build/Makefile.in
index cc53c6e13c1..e7bc8e2bf15 100644
--- a/build/Makefile.in
+++ b/build/Makefile.in
@@ -222,7 +222,6 @@ CORE_SOURCES = \
   src/core/Regex.pm \
   src/core/Junction.pm \
   src/core/Grammar.pm \
-  src/core/Substitution.pm \
   src/core/system.pm \
   src/cheats/process.pm \
   src/core/tai-utc.pm \
diff --git a/src/Perl6/Actions.pm b/src/Perl6/Actions.pm
index 9c7ff47aa3d..9857f754123 100644
--- a/src/Perl6/Actions.pm
+++ b/src/Perl6/Actions.pm
@@ -2709,7 +2709,7 @@ method quote:sym<s>($/) {
     );
     my $closure := block_closure($closure_ast, 'Block', 0);
 
-    # Make a Substitution.
+    # make $_ = $_.subst(...)
     my $past := PAST::Op.new(
         :node($/),
         :pasttype('callmethod'), :name('subst'),
diff --git a/src/core/Substitution.pm b/src/core/Substitution.pm
deleted file mode 100644
index 03f6bd39f38..00000000000
--- a/src/core/Substitution.pm
+++ /dev/null
@@ -1,13 +0,0 @@
-class Substitution {
-    has $!matcher;
-    has $!replacer;
-    has %!adverbs;
-
-    method new(:$matcher, :$replacer, *%adverbs) {
-        self.bless(*, :$matcher, :$replacer, :%adverbs);
-    }
-
-    method ACCEPTS($topic is rw) {
-        $topic = $topic.subst($!matcher, $!replacer, |%!adverbs);
-    }
-}
diff --git a/src/core/operators.pm b/src/core/operators.pm
index 74f8c2391c2..8b21c125261 100644
--- a/src/core/operators.pm
+++ b/src/core/operators.pm
@@ -11,11 +11,6 @@ our multi infix:<~~>(Mu $topic, Regex $matcher) {
     };
 }
 
-class Substitution { ... }
-our multi infix:<~~>(Mu $topic is rw, Substitution $matcher) {
-    $matcher.ACCEPTS($topic)
-}
-
 our multi prefix:<?>(Mu $a) {
     pir::can($a, 'Bool')
     ?? $a.Bool