diff --git a/js/src/jit-test/tests/debug/Debugger-debuggees-19.js b/js/src/jit-test/tests/debug/Debugger-debuggees-19.js
index b32920a7c18d..20d9f1599668 100644
--- a/js/src/jit-test/tests/debug/Debugger-debuggees-19.js
+++ b/js/src/jit-test/tests/debug/Debugger-debuggees-19.js
@@ -6,7 +6,7 @@ var dbg = new Debugger;
 var log;
 dbg.onEnterFrame = function (frame) {
   log += 'e';
-  log += frame.environment.object.label;
+  log += frame.environment.parent.object.label;
 };
 
 var g1 = newGlobal();
diff --git a/js/src/jit-test/tests/debug/Environment-callee-01.js b/js/src/jit-test/tests/debug/Environment-callee-01.js
index 31ee61386275..b3d84ec70a98 100644
--- a/js/src/jit-test/tests/debug/Environment-callee-01.js
+++ b/js/src/jit-test/tests/debug/Environment-callee-01.js
@@ -19,7 +19,7 @@ function check(code, expectedType, expectedCallee) {
   assertEq(hits, 1);
 }
 
-check('debugger;', 'object', null);
+check('debugger;', 'declarative', null);
 check('with({}) { debugger; };', 'with', null);
 check('let (x=1) { debugger; };', 'declarative', null);
 
@@ -30,16 +30,13 @@ g.eval('function g() { h(); }');
 g.eval('function h() { debugger; }');
 check('g()', 'declarative', gw.makeDebuggeeValue(g.h));
 
-// Strict direct eval gets its own environment.
+// All evals get a lexical scope.
 check('"use strict"; eval("debugger");', 'declarative', null);
 g.eval('function j() { "use strict"; eval("debugger;"); }');
 check('j()', 'declarative', null);
 
-// Lenient direct eval shares eval's caller's environment,
-// although this is a great evil.
-check('eval("debugger");', 'object', null);
-g.eval('function k() { eval("debugger;"); }');
-check('k()', 'declarative', gw.makeDebuggeeValue(g.k));
+// All evals get a lexical scope.
+check('eval("debugger");', 'declarative', null);
 
 g.eval('function m() { debugger; yield true; }');
 check('m().next();', 'declarative', gw.makeDebuggeeValue(g.m));
diff --git a/js/src/jit-test/tests/debug/Environment-getVariable-05.js b/js/src/jit-test/tests/debug/Environment-getVariable-05.js
index 500752467512..f4bd52144647 100644
--- a/js/src/jit-test/tests/debug/Environment-getVariable-05.js
+++ b/js/src/jit-test/tests/debug/Environment-getVariable-05.js
@@ -4,7 +4,7 @@ var g = newGlobal();
 var dbg = Debugger(g);
 var log = '';
 dbg.onDebuggerStatement = function (frame) {
-    log += frame.environment.getVariable("x") + frame.environment.getVariable("y");
+    log += frame.environment.parent.getVariable("x") + frame.environment.parent.getVariable("y");
 };
 g.eval("var x = 'a'; this.y = 'b'; debugger;");
 assertEq(log, 'ab');
diff --git a/js/src/jit-test/tests/debug/Environment-getVariable-06.js b/js/src/jit-test/tests/debug/Environment-getVariable-06.js
index de9f0168aa97..096f77d8e3cd 100644
--- a/js/src/jit-test/tests/debug/Environment-getVariable-06.js
+++ b/js/src/jit-test/tests/debug/Environment-getVariable-06.js
@@ -4,7 +4,7 @@ var g = newGlobal();
 var dbg = Debugger(g);
 var log = '';
 dbg.onDebuggerStatement = function (frame) {
-    log += frame.environment.getVariable("x") + frame.environment.getVariable("y");
+    log += frame.environment.parent.getVariable("x") + frame.environment.parent.getVariable("y");
 };
 g.eval("Object.getPrototypeOf(this).x = 'a';\n" +
        "Object.prototype.y = 'b';\n" +
diff --git a/js/src/jit-test/tests/debug/Environment-getVariable-11.js b/js/src/jit-test/tests/debug/Environment-getVariable-11.js
index 9bc9be1a082e..ac144407ebe8 100644
--- a/js/src/jit-test/tests/debug/Environment-getVariable-11.js
+++ b/js/src/jit-test/tests/debug/Environment-getVariable-11.js
@@ -5,7 +5,7 @@ var dbg = new Debugger;
 var gw = dbg.addDebuggee(g);
 var hits = 0;
 dbg.onDebuggerStatement = function (frame) {
-    var a = frame.environment.getVariable('Math');
+    var a = frame.environment.parent.getVariable('Math');
     assertEq(a instanceof Debugger.Object, true);
     var b = gw.getOwnPropertyDescriptor('Math').value;
     assertEq(a, b);
diff --git a/js/src/jit-test/tests/debug/Environment-getVariable-12.js b/js/src/jit-test/tests/debug/Environment-getVariable-12.js
index 0bbf4e3fdff9..b6852bb6fa06 100644
--- a/js/src/jit-test/tests/debug/Environment-getVariable-12.js
+++ b/js/src/jit-test/tests/debug/Environment-getVariable-12.js
@@ -5,7 +5,7 @@ var gw = dbg.addDebuggee(g);
 var hits = 0;
 dbg.onDebuggerStatement = function (frame) {
     hits++;
-    assertEq(frame.environment.parent.getVariable('y'), true);
+    assertEq(frame.environment.parent.parent.getVariable('y'), true);
 };
 
 g.eval("var g;" +
diff --git a/js/src/jit-test/tests/debug/Environment-getVariable-WouldRun.js b/js/src/jit-test/tests/debug/Environment-getVariable-WouldRun.js
index 457f2904cd8b..8d2457d12fab 100644
--- a/js/src/jit-test/tests/debug/Environment-getVariable-WouldRun.js
+++ b/js/src/jit-test/tests/debug/Environment-getVariable-WouldRun.js
@@ -8,7 +8,7 @@ var dbg = Debugger(g);
 var hits = 0;
 dbg.onDebuggerStatement = function (frame) {
     assertThrowsInstanceOf(function () {
-        frame.environment.getVariable("x");
+        frame.environment.parent.getVariable("x");
     }, Error);
     hits++;
 };
diff --git a/js/src/jit-test/tests/debug/Environment-identity-03.js b/js/src/jit-test/tests/debug/Environment-identity-03.js
index 1087d5c6b6de..3f7e843c1878 100644
--- a/js/src/jit-test/tests/debug/Environment-identity-03.js
+++ b/js/src/jit-test/tests/debug/Environment-identity-03.js
@@ -51,7 +51,7 @@ function test(sharedName, expectedHits, code) {
 // the optimization or with the debugger exposing it, but that's not what we
 // want to test here.)
 
-test("q", 2, "var q = function (a) { h(); }; q(1); q(2);");
+test("q", 2, "let q = function (a) { h(); }; q(1); q(2);");
 test("a", 2, "q = function (a) { (function (b) { h(); a = b; })(2); h(); }; q(1);");
 test("a", 2, "q = function (a) { h(); return function (b) { h(); a = b; }; }; q(1)(2);");
 test("n", 3, "q = function (n) { for (var i = 0; i < n; i++) { let (j = i) { h(); } } }; q(3);");
diff --git a/js/src/jit-test/tests/debug/Environment-inspectable-01.js b/js/src/jit-test/tests/debug/Environment-inspectable-01.js
index 4e80f6285a39..ee5897833d51 100644
--- a/js/src/jit-test/tests/debug/Environment-inspectable-01.js
+++ b/js/src/jit-test/tests/debug/Environment-inspectable-01.js
@@ -45,7 +45,8 @@ function debuggerHandler(frame) {
   assertEq(ke.inspectable, true);
   assertEq(ke.getVariable('xk'), 'value of xk');
   assertEq(ee.inspectable, true);
-  assertEq(ee.type, 'object');
+  assertEq(ee.type, 'declarative');
+  assertEq(ee.parent.type, 'object');
 
   dbg.removeDebuggee(g2);
 
@@ -54,7 +55,8 @@ function debuggerHandler(frame) {
   assertEq(ke.inspectable, false);
   assertThrowsInstanceOf(() => ke.getVariable('xk'), Error);
   assertEq(ee.inspectable, true);
-  assertEq(ee.type, 'object');
+  assertEq(ee.type, 'declarative');
+  assertEq(ee.parent.type, 'object');
 
   dbg.removeDebuggee(g1);
 
diff --git a/js/src/jit-test/tests/debug/Environment-nondebuggee.js b/js/src/jit-test/tests/debug/Environment-nondebuggee.js
index 3d1951dcae35..72d4ae9909cf 100644
--- a/js/src/jit-test/tests/debug/Environment-nondebuggee.js
+++ b/js/src/jit-test/tests/debug/Environment-nondebuggee.js
@@ -35,6 +35,6 @@ assertEq(log, 'd');
 dbg.addDebuggee(g);
 g.eval('function f() { }');
 let env = gw.getOwnPropertyDescriptor('f').value.environment;
-assertEq(env.type, 'object');
+assertEq(env.type, 'declarative');
 dbg.removeDebuggee(g);
 check(env);
diff --git a/js/src/jit-test/tests/debug/Environment-optimizedOut-01.js b/js/src/jit-test/tests/debug/Environment-optimizedOut-01.js
index df7a6087e8e2..7701ebc073af 100644
--- a/js/src/jit-test/tests/debug/Environment-optimizedOut-01.js
+++ b/js/src/jit-test/tests/debug/Environment-optimizedOut-01.js
@@ -28,7 +28,7 @@ dbg.onEnterFrame = function (f) {
     assertEq(funenv.callee, f.older.callee);
     assertEq(funenv.names().indexOf("x") !== -1, true);
 
-    globalenv = funenv.parent;
+    globalenv = funenv.parent.parent;
     assertEq(globalenv.optimizedOut, false);
     assertEq(globalenv.inspectable, true);
     assertEq(globalenv.type, "object");
diff --git a/js/src/jit-test/tests/debug/Environment-setVariable-01.js b/js/src/jit-test/tests/debug/Environment-setVariable-01.js
index 007bd2dad1ae..610960241cc3 100644
--- a/js/src/jit-test/tests/debug/Environment-setVariable-01.js
+++ b/js/src/jit-test/tests/debug/Environment-setVariable-01.js
@@ -3,7 +3,7 @@
 var g = newGlobal();
 var dbg = Debugger(g);
 dbg.onDebuggerStatement = function (frame) {
-    frame.environment.setVariable("x", 2);
+    frame.environment.parent.setVariable("x", 2);
 };
 g.eval("var x = 1; debugger;");
 assertEq(g.x, 2);
diff --git a/js/src/jit-test/tests/debug/Environment-setVariable-02.js b/js/src/jit-test/tests/debug/Environment-setVariable-02.js
index 7e4e61906ee5..02494609e260 100644
--- a/js/src/jit-test/tests/debug/Environment-setVariable-02.js
+++ b/js/src/jit-test/tests/debug/Environment-setVariable-02.js
@@ -4,7 +4,7 @@ var g = newGlobal();
 var dbg = new Debugger;
 var gw = dbg.addDebuggee(g);
 dbg.onDebuggerStatement = function (frame) {
-    frame.environment.setVariable("x", gw);
+    frame.environment.parent.setVariable("x", gw);
 };
 g.eval("var x = 1; debugger;");
 assertEq(g.x, g);
diff --git a/js/src/jit-test/tests/debug/Environment-type-01.js b/js/src/jit-test/tests/debug/Environment-type-01.js
index 3fdd1e2dbae5..3085163c29f0 100644
--- a/js/src/jit-test/tests/debug/Environment-type-01.js
+++ b/js/src/jit-test/tests/debug/Environment-type-01.js
@@ -9,7 +9,7 @@ function test(code, expected) {
     assertEq(actual, expected);
 }
 
-test("h();", 'object');
+test("h();", 'declarative');
 test("(function (s) { eval(s); })('var v = h();')", 'declarative');
 test("(function (s) { h(); })();", 'declarative');
 test("{let x = 1, y = 2; h();}", 'declarative');
@@ -17,7 +17,7 @@ test("with({x: 1, y: 2}) h();", 'with');
 test("(function (s) { with ({x: 1, y: 2}) h(); })();", 'with');
 test("let (x = 1) { h(); }", 'declarative');
 test("for (let x = 0; x < 1; x++) h();", 'declarative');
-test("for (let x in h()) ;", 'object');
+test("for (let x in h()) ;", 'declarative');
 test("for (let x in {a:1}) h();", 'declarative');
 test("try { throw new Error; } catch (x) { h(x) }", 'declarative');
 test("'use strict'; eval('var z = 1; h();');", 'declarative');
@@ -33,5 +33,5 @@ test("for (var x in (0 for (m in h()))) ;", 'declarative');
 dbg.onDebuggerStatement = function (frame) {
     assertEq(frame.eval("h(), 2 + 2;").return, 4);
 }
-test("debugger;", 'object');
+test("debugger;", 'declarative');
 test("(function f() { debugger; })();", 'declarative');
diff --git a/js/src/jit-test/tests/debug/Frame-environment-02.js b/js/src/jit-test/tests/debug/Frame-environment-02.js
index 9909be80aa9a..6d6101c59a47 100644
--- a/js/src/jit-test/tests/debug/Frame-environment-02.js
+++ b/js/src/jit-test/tests/debug/Frame-environment-02.js
@@ -4,7 +4,7 @@ var g = newGlobal();
 var dbg = new Debugger;
 var gw = dbg.addDebuggee(g);
 g.h = function () {
-    var env = dbg.getNewestFrame().environment;
+    var env = dbg.getNewestFrame().environment.parent;
     assertEq(env instanceof Debugger.Environment, true);
     assertEq(env.object, gw);
     assertEq(env.parent, null);
diff --git a/js/src/jit-test/tests/debug/Memory-takeCensus-10.js b/js/src/jit-test/tests/debug/Memory-takeCensus-10.js
index 79474da1ff14..aa811184deb2 100644
--- a/js/src/jit-test/tests/debug/Memory-takeCensus-10.js
+++ b/js/src/jit-test/tests/debug/Memory-takeCensus-10.js
@@ -6,7 +6,7 @@ let dbg = new Debugger(g);
 let sizeOfAM = byteSize(allocationMarker());
 
 // Allocate a single allocation marker, and check that we can find it.
-g.eval('let hold = allocationMarker();');
+g.eval('var hold = allocationMarker();');
 let census = dbg.memory.takeCensus({ breakdown: { by: 'objectClass' } });
 assertEq(census.AllocationMarker.count, 1);
 assertEq(census.AllocationMarker.bytes, sizeOfAM);
diff --git a/js/src/jit-test/tests/debug/Object-getOwnPropertyDescriptor-03.js b/js/src/jit-test/tests/debug/Object-getOwnPropertyDescriptor-03.js
index 3be271b927df..78f5d9efa2ae 100644
--- a/js/src/jit-test/tests/debug/Object-getOwnPropertyDescriptor-03.js
+++ b/js/src/jit-test/tests/debug/Object-getOwnPropertyDescriptor-03.js
@@ -1,8 +1,8 @@
 // obj.getOwnPropertyDescriptor works on global objects.
 
 var g = newGlobal();
-g.eval("var v; const k = 42;");
-this.eval("var v; const k = 42;");
+g.eval("var v;");
+this.eval("var v;");
 
 var dbg = Debugger();
 var obj = dbg.addDebuggee(g);
@@ -20,4 +20,3 @@ function test(name) {
 
 test("Infinity");
 test("v");
-test("k");