diff --git a/src/test/auxiliary/issue_2723_a.rs b/src/test/auxiliary/issue_2723_a.rs
new file mode 100644
index 0000000000000..51ec1cb4b9b44
--- /dev/null
+++ b/src/test/auxiliary/issue_2723_a.rs
@@ -0,0 +1,3 @@
+unsafe fn f(xs: ~[int]) {
+  xs.map(|_x| { unsafe fn q() { fail; } });
+}
\ No newline at end of file
diff --git a/src/test/run-pass/issue-2723-b.rs b/src/test/run-pass/issue-2723-b.rs
new file mode 100644
index 0000000000000..895a0df19e70c
--- /dev/null
+++ b/src/test/run-pass/issue-2723-b.rs
@@ -0,0 +1,8 @@
+// aux-build:issue_2723_a.rs
+
+use issue_2723_a;
+import issue_2723_a::*;
+
+fn main() unsafe {
+  f(~[2]);
+}
\ No newline at end of file