diff --git a/src/parser/statement.js b/src/parser/statement.js
index cde86295ab..da148c18f2 100644
--- a/src/parser/statement.js
+++ b/src/parser/statement.js
@@ -763,8 +763,13 @@ pp.parseClassBody = function (node) {
 };
 
 pp.parseClassProperty = function (node) {
+  const noPluginMsg = "You can only use Class Properties when the 'classProperties' plugin is enabled.";
+  if (!node.typeAnnotation && !this.hasPlugin("classProperties")) {
+    this.raise(node.start, noPluginMsg);
+  }
+
   if (this.match(tt.eq)) {
-    if (!this.hasPlugin("classProperties")) this.unexpected();
+    if (!this.hasPlugin("classProperties")) this.raise(this.state.start, noPluginMsg);
     this.next();
     node.value = this.parseMaybeAssign();
   } else {
diff --git a/test/fixtures/experimental/class-properties/with-initializer-and-type-no-plugin/actual.js b/test/fixtures/experimental/class-properties/with-initializer-and-type-no-plugin/actual.js
new file mode 100644
index 0000000000..f82f8d51d7
--- /dev/null
+++ b/test/fixtures/experimental/class-properties/with-initializer-and-type-no-plugin/actual.js
@@ -0,0 +1,3 @@
+class Foo {
+  bar: string = 'bizz';
+}
diff --git a/test/fixtures/experimental/class-properties/with-initializer-and-type-no-plugin/options.json b/test/fixtures/experimental/class-properties/with-initializer-and-type-no-plugin/options.json
new file mode 100644
index 0000000000..e185feb80a
--- /dev/null
+++ b/test/fixtures/experimental/class-properties/with-initializer-and-type-no-plugin/options.json
@@ -0,0 +1,4 @@
+{
+  "plugins": ["flow"],
+  "throws": "You can only use Class Properties when the 'classProperties' plugin is enabled. (2:14)"
+}
diff --git a/test/fixtures/experimental/class-properties/with-initializer-missing-plugin/actual.js b/test/fixtures/experimental/class-properties/with-initializer-missing-plugin/actual.js
new file mode 100644
index 0000000000..fa80e3af68
--- /dev/null
+++ b/test/fixtures/experimental/class-properties/with-initializer-missing-plugin/actual.js
@@ -0,0 +1,3 @@
+class Foo {
+  bar = 'bizz';
+}
diff --git a/test/fixtures/experimental/class-properties/with-initializer-missing-plugin/options.json b/test/fixtures/experimental/class-properties/with-initializer-missing-plugin/options.json
new file mode 100644
index 0000000000..af38bd1530
--- /dev/null
+++ b/test/fixtures/experimental/class-properties/with-initializer-missing-plugin/options.json
@@ -0,0 +1,3 @@
+{
+  "throws": "You can only use Class Properties when the 'classProperties' plugin is enabled. (2:2)"
+}
diff --git a/test/fixtures/experimental/class-properties/without-initializer-missing-plugin/actual.js b/test/fixtures/experimental/class-properties/without-initializer-missing-plugin/actual.js
new file mode 100644
index 0000000000..a36cdd975c
--- /dev/null
+++ b/test/fixtures/experimental/class-properties/without-initializer-missing-plugin/actual.js
@@ -0,0 +1,3 @@
+class Foo {
+  bar;
+}
diff --git a/test/fixtures/experimental/class-properties/without-initializer-missing-plugin/options.json b/test/fixtures/experimental/class-properties/without-initializer-missing-plugin/options.json
new file mode 100644
index 0000000000..af38bd1530
--- /dev/null
+++ b/test/fixtures/experimental/class-properties/without-initializer-missing-plugin/options.json
@@ -0,0 +1,3 @@
+{
+  "throws": "You can only use Class Properties when the 'classProperties' plugin is enabled. (2:2)"
+}