diff --git a/src/test/ui/mir/issue-66930.rs b/src/test/ui/mir/issue-66930.rs
new file mode 100644
index 0000000000000..5f9eb2bf437fd
--- /dev/null
+++ b/src/test/ui/mir/issue-66930.rs
@@ -0,0 +1,11 @@
+// check-pass
+// compile-flags: --emit=mir,link
+// Regression test for #66930, this ICE requires `--emit=mir` flag.
+
+static UTF8_CHAR_WIDTH: [u8; 0] = [];
+
+pub fn utf8_char_width(b: u8) -> usize {
+    UTF8_CHAR_WIDTH[b as usize] as usize
+}
+
+fn main() {}