diff --git a/src/rt/rust_builtin.cpp b/src/rt/rust_builtin.cpp
index f586e05772b76..3c6cc9d924522 100644
--- a/src/rt/rust_builtin.cpp
+++ b/src/rt/rust_builtin.cpp
@@ -866,6 +866,16 @@ rust_dbg_extern_identity_TwoU64s(TwoU64s u) {
     return u;
 }
 
+struct TwoDoubles {
+    double one;
+    double two;
+};
+
+extern "C" CDECL TwoDoubles
+rust_dbg_extern_identity_TwoDoubles(TwoDoubles u) {
+    return u;
+}
+
 extern "C" CDECL double
 rust_dbg_extern_identity_double(double u) {
     return u;
diff --git a/src/rt/rustrt.def.in b/src/rt/rustrt.def.in
index 59fd8991622c6..73dbe661d3f86 100644
--- a/src/rt/rustrt.def.in
+++ b/src/rt/rustrt.def.in
@@ -199,6 +199,7 @@ rust_opendir
 rust_dbg_extern_identity_u32
 rust_dbg_extern_identity_u64
 rust_dbg_extern_identity_TwoU64s
+rust_dbg_extern_identity_TwoDoubles
 rust_dbg_extern_identity_double
 rust_dbg_extern_identity_u8
 rust_get_rt_env
diff --git a/src/test/run-pass/issue-5754.rs b/src/test/run-pass/issue-5754.rs
index 003701b7a20cb..c440fe525eef9 100644
--- a/src/test/run-pass/issue-5754.rs
+++ b/src/test/run-pass/issue-5754.rs
@@ -8,12 +8,13 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-struct S {
-    r: float
+struct TwoDoubles {
+    r: float,
+    i: float
 }
 
 extern "C" {
-    fn rust_dbg_extern_identity_double(arg1: S) -> float;
+    fn rust_dbg_extern_identity_TwoDoubles(arg1: TwoDoubles) -> TwoDoubles;
 }
 
 pub fn main() {}