diff --git a/tests/cases/fourslash/changeExtendsToImplementsFS1.ts b/tests/cases/fourslash/codeFixChangeExtendsToImplementsFS1.ts
similarity index 100%
rename from tests/cases/fourslash/changeExtendsToImplementsFS1.ts
rename to tests/cases/fourslash/codeFixChangeExtendsToImplementsFS1.ts
diff --git a/tests/cases/fourslash/changeExtendsToImplementsFS2.ts b/tests/cases/fourslash/codeFixChangeExtendsToImplementsFS2.ts
similarity index 100%
rename from tests/cases/fourslash/changeExtendsToImplementsFS2.ts
rename to tests/cases/fourslash/codeFixChangeExtendsToImplementsFS2.ts
diff --git a/tests/cases/fourslash/codeFixClassExtendsAbstractNumber.ts b/tests/cases/fourslash/codeFixClassExtendsAbstractNumber.ts
new file mode 100644
index 00000000000..134c1979dce
--- /dev/null
+++ b/tests/cases/fourslash/codeFixClassExtendsAbstractNumber.ts
@@ -0,0 +1,11 @@
+/// <reference path='fourslash.ts' />
+
+//// abstract class A {
+////    abstract x: number;
+//// }
+////
+//// class C extends A {[|
+//// |]}
+
+verify.codeFixAtPosition(`x: number;
+`);