diff --git a/src/compiler/transformers/es2015.ts b/src/compiler/transformers/es2015.ts
index a430476958e..734fbcaeb16 100644
--- a/src/compiler/transformers/es2015.ts
+++ b/src/compiler/transformers/es2015.ts
@@ -3780,7 +3780,7 @@ namespace ts {
         function substituteExpressionIdentifier(node: Identifier): Identifier {
             if (enabledSubstitutions & ES2015SubstitutionFlags.BlockScopedBindings && !isInternalName(node)) {
                 const declaration = resolver.getReferencedDeclarationWithCollidingName(node);
-                if (declaration) {
+                if (declaration && !(isClassLike(declaration) && isPartOfClassBody(declaration, node))) {
                     return setTextRange(getGeneratedNameForNode(declaration.name), node);
                 }
             }
@@ -3788,6 +3788,32 @@ namespace ts {
             return node;
         }
 
+        function isPartOfClassBody(declaration: ClassLikeDeclaration, node: Identifier) {
+            let currentNode = getParseTreeNode(node);
+            if (!currentNode || currentNode === declaration || currentNode.end <= declaration.pos || currentNode.pos >= declaration.end) {
+                // if the node has no correlation to a parse tree node, its definitely not
+                // part of the body.
+                // if the node is outside of the document range of the declaration, its
+                // definitely not part of the body.
+                return false;
+            }
+            const blockScope = getEnclosingBlockScopeContainer(declaration);
+            while (currentNode) {
+                if (currentNode === blockScope || currentNode === declaration) {
+                    // if we are in the enclosing block scope of the declaration, we are definitely
+                    // not inside the class body.
+                    return false;
+                }
+                if (isClassElement(currentNode) && currentNode.parent === declaration) {
+                    // we are in the class body, but we treat static fields as outside of the class body
+                    return currentNode.kind !== SyntaxKind.PropertyDeclaration
+                        || (getModifierFlags(currentNode) & ModifierFlags.Static) === 0;
+                }
+                currentNode = currentNode.parent;
+            }
+            return false;
+        }
+
         /**
          * Substitutes `this` when contained within an arrow function.
          *
@@ -3803,7 +3829,7 @@ namespace ts {
 
         function getClassMemberPrefix(node: ClassExpression | ClassDeclaration, member: ClassElement) {
             return hasModifier(member, ModifierFlags.Static)
-                ? getLocalName(node)
+                ? getInternalName(node)
                 : createPropertyAccess(getInternalName(node), "prototype");
         }
 
diff --git a/tests/baselines/reference/classBlockScoping.js b/tests/baselines/reference/classBlockScoping.js
new file mode 100644
index 00000000000..76d0dd892de
--- /dev/null
+++ b/tests/baselines/reference/classBlockScoping.js
@@ -0,0 +1,71 @@
+//// [classBlockScoping.ts]
+function f(b: boolean) {
+  let Foo: any;
+  if (b) {
+    Foo = class Foo {
+      static y = new Foo();
+
+      static x() {
+        new Foo();
+      }
+
+      m() {
+        new Foo();
+      }
+    };
+
+    new Foo();
+  }
+  else {
+    class Foo {
+      static y = new Foo();
+
+      static x() {
+        new Foo();
+      }
+
+      m() {
+        new Foo();
+      }
+    }
+
+    new Foo();
+  }
+}
+
+//// [classBlockScoping.js]
+function f(b) {
+    var Foo;
+    if (b) {
+        Foo = (_a = (function () {
+                function Foo() {
+                }
+                Foo.x = function () {
+                    new Foo();
+                };
+                Foo.prototype.m = function () {
+                    new Foo();
+                };
+                return Foo;
+            }()),
+            _a.y = new _a(),
+            _a);
+        new Foo();
+    }
+    else {
+        var Foo_1 = (function () {
+            function Foo() {
+            }
+            Foo.x = function () {
+                new Foo();
+            };
+            Foo.prototype.m = function () {
+                new Foo();
+            };
+            return Foo;
+        }());
+        Foo_1.y = new Foo_1();
+        new Foo_1();
+    }
+    var _a;
+}
diff --git a/tests/baselines/reference/classBlockScoping.symbols b/tests/baselines/reference/classBlockScoping.symbols
new file mode 100644
index 00000000000..571d54f2d8e
--- /dev/null
+++ b/tests/baselines/reference/classBlockScoping.symbols
@@ -0,0 +1,64 @@
+=== tests/cases/compiler/classBlockScoping.ts ===
+function f(b: boolean) {
+>f : Symbol(f, Decl(classBlockScoping.ts, 0, 0))
+>b : Symbol(b, Decl(classBlockScoping.ts, 0, 11))
+
+  let Foo: any;
+>Foo : Symbol(Foo, Decl(classBlockScoping.ts, 1, 5))
+
+  if (b) {
+>b : Symbol(b, Decl(classBlockScoping.ts, 0, 11))
+
+    Foo = class Foo {
+>Foo : Symbol(Foo, Decl(classBlockScoping.ts, 1, 5))
+>Foo : Symbol(Foo, Decl(classBlockScoping.ts, 3, 9))
+
+      static y = new Foo();
+>y : Symbol(Foo.y, Decl(classBlockScoping.ts, 3, 21))
+>Foo : Symbol(Foo, Decl(classBlockScoping.ts, 3, 9))
+
+      static x() {
+>x : Symbol(Foo.x, Decl(classBlockScoping.ts, 4, 27))
+
+        new Foo();
+>Foo : Symbol(Foo, Decl(classBlockScoping.ts, 3, 9))
+      }
+
+      m() {
+>m : Symbol(Foo.m, Decl(classBlockScoping.ts, 8, 7))
+
+        new Foo();
+>Foo : Symbol(Foo, Decl(classBlockScoping.ts, 3, 9))
+      }
+    };
+
+    new Foo();
+>Foo : Symbol(Foo, Decl(classBlockScoping.ts, 1, 5))
+  }
+  else {
+    class Foo {
+>Foo : Symbol(Foo, Decl(classBlockScoping.ts, 17, 8))
+
+      static y = new Foo();
+>y : Symbol(Foo.y, Decl(classBlockScoping.ts, 18, 15))
+>Foo : Symbol(Foo, Decl(classBlockScoping.ts, 17, 8))
+
+      static x() {
+>x : Symbol(Foo.x, Decl(classBlockScoping.ts, 19, 27))
+
+        new Foo();
+>Foo : Symbol(Foo, Decl(classBlockScoping.ts, 17, 8))
+      }
+
+      m() {
+>m : Symbol(Foo.m, Decl(classBlockScoping.ts, 23, 7))
+
+        new Foo();
+>Foo : Symbol(Foo, Decl(classBlockScoping.ts, 17, 8))
+      }
+    }
+
+    new Foo();
+>Foo : Symbol(Foo, Decl(classBlockScoping.ts, 17, 8))
+  }
+}
diff --git a/tests/baselines/reference/classBlockScoping.types b/tests/baselines/reference/classBlockScoping.types
new file mode 100644
index 00000000000..a54499d7400
--- /dev/null
+++ b/tests/baselines/reference/classBlockScoping.types
@@ -0,0 +1,74 @@
+=== tests/cases/compiler/classBlockScoping.ts ===
+function f(b: boolean) {
+>f : (b: boolean) => void
+>b : boolean
+
+  let Foo: any;
+>Foo : any
+
+  if (b) {
+>b : boolean
+
+    Foo = class Foo {
+>Foo = class Foo {      static y = new Foo();      static x() {        new Foo();      }      m() {        new Foo();      }    } : typeof Foo
+>Foo : any
+>class Foo {      static y = new Foo();      static x() {        new Foo();      }      m() {        new Foo();      }    } : typeof Foo
+>Foo : typeof Foo
+
+      static y = new Foo();
+>y : Foo
+>new Foo() : Foo
+>Foo : typeof Foo
+
+      static x() {
+>x : () => void
+
+        new Foo();
+>new Foo() : Foo
+>Foo : typeof Foo
+      }
+
+      m() {
+>m : () => void
+
+        new Foo();
+>new Foo() : Foo
+>Foo : typeof Foo
+      }
+    };
+
+    new Foo();
+>new Foo() : any
+>Foo : any
+  }
+  else {
+    class Foo {
+>Foo : Foo
+
+      static y = new Foo();
+>y : Foo
+>new Foo() : Foo
+>Foo : typeof Foo
+
+      static x() {
+>x : () => void
+
+        new Foo();
+>new Foo() : Foo
+>Foo : typeof Foo
+      }
+
+      m() {
+>m : () => void
+
+        new Foo();
+>new Foo() : Foo
+>Foo : typeof Foo
+      }
+    }
+
+    new Foo();
+>new Foo() : Foo
+>Foo : typeof Foo
+  }
+}
diff --git a/tests/cases/compiler/classBlockScoping.ts b/tests/cases/compiler/classBlockScoping.ts
new file mode 100644
index 00000000000..d4620fc89c8
--- /dev/null
+++ b/tests/cases/compiler/classBlockScoping.ts
@@ -0,0 +1,33 @@
+function f(b: boolean) {
+  let Foo: any;
+  if (b) {
+    Foo = class Foo {
+      static y = new Foo();
+
+      static x() {
+        new Foo();
+      }
+
+      m() {
+        new Foo();
+      }
+    };
+
+    new Foo();
+  }
+  else {
+    class Foo {
+      static y = new Foo();
+
+      static x() {
+        new Foo();
+      }
+
+      m() {
+        new Foo();
+      }
+    }
+
+    new Foo();
+  }
+}
\ No newline at end of file