diff --git a/changelog_unreleased/javascript/11750.md b/changelog_unreleased/javascript/11750.md
index a63b9849c..e36df4ac2 100644
--- a/changelog_unreleased/javascript/11750.md
+++ b/changelog_unreleased/javascript/11750.md
@@ -1,4 +1,4 @@
-#### Ignore errors for non-strict mode features (#11750 by @fisker, #11778 by @sosukesuzuki)
+#### Ignore errors for sloppy mode syntax (#11750 by @fisker, #11778 by @sosukesuzuki)
 
 <!-- prettier-ignore -->
 ```jsx
diff --git a/tests/format/js/sloppy-mode/__snapshots__/jsfmt.spec.js.snap b/tests/format/js/sloppy-mode/__snapshots__/jsfmt.spec.js.snap
index d71b4a460..0da7ef0e8 100644
--- a/tests/format/js/sloppy-mode/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/format/js/sloppy-mode/__snapshots__/jsfmt.spec.js.snap
@@ -59,6 +59,55 @@ function myfunc() {
 ================================================================================
 `;
 
+exports[`function-declaration-in-lf.js format 1`] = `
+====================================options=====================================
+parsers: ["babel", "flow", "typescript"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+if (false) function foo(){}
+
+=====================================output=====================================
+if (false) function foo() {}
+
+================================================================================
+`;
+
+exports[`function-declaration-in-while.js [espree] format 1`] = `
+"Unexpected token function (1:15)
+> 1 | while (false) function foo(){}
+    |               ^
+  2 |"
+`;
+
+exports[`function-declaration-in-while.js [flow] format 1`] = `
+"In non-strict mode code, functions can only be declared at top level, inside a block, or as the body of an if statement. (1:15)
+> 1 | while (false) function foo(){}
+    |               ^^^^^^^^^^^^^^^^
+  2 |"
+`;
+
+exports[`function-declaration-in-while.js [meriyah] format 1`] = `
+"[1:22]: In strict mode code, functions can only be declared at top level or inside a block (1:22)
+> 1 | while (false) function foo(){}
+    |                      ^
+  2 |"
+`;
+
+exports[`function-declaration-in-while.js format 1`] = `
+====================================options=====================================
+parsers: ["babel", "flow", "typescript"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+while (false) function foo(){}
+
+=====================================output=====================================
+while (false) function foo() {}
+
+================================================================================
+`;
+
 exports[`labeled-function-declaration.js format 1`] = `
 ====================================options=====================================
 parsers: ["babel", "flow", "typescript"]
diff --git a/tests/format/js/sloppy-mode/function-declaration-in-lf.js b/tests/format/js/sloppy-mode/function-declaration-in-lf.js
new file mode 100644
index 000000000..86b863d3e
--- /dev/null
+++ b/tests/format/js/sloppy-mode/function-declaration-in-lf.js
@@ -0,0 +1 @@
+if (false) function foo(){}
diff --git a/tests/format/js/sloppy-mode/function-declaration-in-while.js b/tests/format/js/sloppy-mode/function-declaration-in-while.js
new file mode 100644
index 000000000..ce577f802
--- /dev/null
+++ b/tests/format/js/sloppy-mode/function-declaration-in-while.js
@@ -0,0 +1 @@
+while (false) function foo(){}
diff --git a/tests/format/js/sloppy-mode/jsfmt.spec.js b/tests/format/js/sloppy-mode/jsfmt.spec.js
index eb85eda6b..687600bb8 100644
--- a/tests/format/js/sloppy-mode/jsfmt.spec.js
+++ b/tests/format/js/sloppy-mode/jsfmt.spec.js
@@ -1 +1,7 @@
-run_spec(__dirname, ["babel", "flow", "typescript"]);
+run_spec(__dirname, ["babel", "flow", "typescript"], {
+  errors: {
+    flow: ["function-declaration-in-while.js"],
+    espree: ["function-declaration-in-while.js"],
+    meriyah: ["function-declaration-in-while.js"],
+  },
+});