diff --git a/Tests/CMakeLists.txt b/Tests/CMakeLists.txt
index abe742ee6d..3540aaa8ff 100644
--- a/Tests/CMakeLists.txt
+++ b/Tests/CMakeLists.txt
@@ -394,6 +394,9 @@ if(BUILD_TESTING)
     if(CMake_TEST_XCODE_SWIFT)
       ADD_TEST_MACRO(SwiftMix SwiftMix)
     endif()
+    if(CMAKE_Swift_COMPILER_VERSION VERSION_GREATER_EQUAL 5.1)
+      ADD_TEST_MACRO(SwiftMixLib Swifty)
+    endif()
   endif()
   if(CMAKE_Fortran_COMPILER)
     ADD_TEST_MACRO(FortranOnly FortranOnly)
diff --git a/Tests/SwiftMixLib/CMakeLists.txt b/Tests/SwiftMixLib/CMakeLists.txt
new file mode 100644
index 0000000000..40d3498d50
--- /dev/null
+++ b/Tests/SwiftMixLib/CMakeLists.txt
@@ -0,0 +1,6 @@
+cmake_minimum_required(VERSION 3.24)
+project(SwiftMixLib C CXX Swift)
+
+add_library(SwiftMixedLib lib.c lib.cpp lib.swift)
+add_executable(Swifty main.swift)
+target_link_libraries(Swifty PUBLIC SwiftMixedLib)
diff --git a/Tests/SwiftMixLib/lib.c b/Tests/SwiftMixLib/lib.c
new file mode 100644
index 0000000000..8eca512464
--- /dev/null
+++ b/Tests/SwiftMixLib/lib.c
@@ -0,0 +1,4 @@
+int add_int(int a, int b)
+{
+  return a + b;
+}
diff --git a/Tests/SwiftMixLib/lib.cpp b/Tests/SwiftMixLib/lib.cpp
new file mode 100644
index 0000000000..3e156b80be
--- /dev/null
+++ b/Tests/SwiftMixLib/lib.cpp
@@ -0,0 +1,4 @@
+int add(int a, int b)
+{
+  return a + b;
+}
diff --git a/Tests/SwiftMixLib/lib.swift b/Tests/SwiftMixLib/lib.swift
new file mode 100644
index 0000000000..61009d876b
--- /dev/null
+++ b/Tests/SwiftMixLib/lib.swift
@@ -0,0 +1,3 @@
+public func add(a: Int, b: Int) -> Int {
+    a + b
+}
diff --git a/Tests/SwiftMixLib/main.swift b/Tests/SwiftMixLib/main.swift
new file mode 100644
index 0000000000..d2e93645d3
--- /dev/null
+++ b/Tests/SwiftMixLib/main.swift
@@ -0,0 +1,3 @@
+import SwiftMixedLib
+
+print(add(a: 1, b: 2))