diff --git a/clang/test/C/C99/block-scopes.c b/clang/test/C/C99/block-scopes.c
new file mode 100644
index 0000000000000..589047df3e52b
--- /dev/null
+++ b/clang/test/C/C99/block-scopes.c
@@ -0,0 +1,34 @@
+// RUN: %clang_cc1 -std=c89 -verify %s
+// RUN: %clang_cc1 -std=c99 -verify %s
+// RUN: %clang_cc1 -std=c11 -verify %s
+// RUN: %clang_cc1 -std=c17 -verify %s
+// RUN: %clang_cc1 -std=c23 -verify %s
+
+// expected-no-diagnostics
+
+/* WG14 ???: yes
+ * new block scopes for selection and iteration statements
+ *
+ * This is referenced in the C99 front matter as new changes to C99, but it is
+ * not clear which document number introduced the changes. It's possible this
+ * is WG14 N759, based on discussion in the C99 rationale document that claims
+ * these changes were made in response to surprising issues with the lifetime
+ * of compound literals in compound statements vs non-compound statements.
+ */
+
+enum {a, b};
+void different(void) {
+  if (sizeof(enum {b, a}) != sizeof(int))
+    _Static_assert(a == 1, "");
+  /* In C89, the 'b' found here would have been from the enum declaration in
+   * the controlling expression of the selection statement, not from the global
+   * declaration. In C99 and later, that enumeration is scoped to the 'if'
+   * statement and the global declaration is what's found.
+   */
+  #if __STDC_VERSION__ >= 199901L
+    _Static_assert(b == 1, "");
+  #else
+    _Static_assert(b == 0, "");
+  #endif
+}
+
diff --git a/clang/www/c_status.html b/clang/www/c_status.html
index 435897277c493..60f48aba2788e 100644
--- a/clang/www/c_status.html
+++ b/clang/www/c_status.html
@@ -260,7 +260,7 @@ <h2 id="c99">C99 implementation status</h2>
     <tr>
       <td>new block scopes for selection and iteration statements</td>
       <td>Unknown</td>
-      <td class="unknown" align="center">Unknown</td>
+      <td class="full" align="center">Yes</td>
     </tr>
     <tr>
       <td>integer constant type rules</td>