diff --git a/include/boost/fiber/fiber.hpp b/include/boost/fiber/fiber.hpp
index d6d32296..7c1ac587 100644
--- a/include/boost/fiber/fiber.hpp
+++ b/include/boost/fiber/fiber.hpp
@@ -361,8 +361,7 @@ public:
 
     void priority( int) BOOST_NOEXCEPT;
 
-    void detach() BOOST_NOEXCEPT
-    { impl_.reset(); }
+    void detach() BOOST_NOEXCEPT;
 
     void join();
 
diff --git a/src/fiber.cpp b/src/fiber.cpp
index e6d1914e..f7f4243c 100644
--- a/src/fiber.cpp
+++ b/src/fiber.cpp
@@ -69,6 +69,21 @@ fiber::join()
     impl_.reset();
 }
 
+void
+fiber::detach() BOOST_NOEXCEPT
+{
+    BOOST_ASSERT( impl_);
+
+    if ( ! joinable() )
+    {
+        boost::throw_exception(
+            fiber_resource_error(
+                system::errc::invalid_argument, "boost fiber: fiber not joinable") );
+    }
+
+    impl_.reset();
+}
+
 void
 fiber::interrupt() BOOST_NOEXCEPT
 {