diff --git a/src/exec.cpp b/src/exec.cpp
index c6115c477..75af77921 100644
--- a/src/exec.cpp
+++ b/src/exec.cpp
@@ -1106,7 +1106,7 @@ static int exec_subshell_internal(const wcstring &cmd, parser_t &parser, wcstrin
         io_buffer_t::create(STDOUT_FILENO, io_chain_t(), is_subcmd ? read_byte_limit : 0));
     if (io_buffer.get() != NULL) {
         parser_t &parser = parser_t::principal_parser();
-        if (parser.eval(cmd, io_chain_t(io_buffer), SUBST) == 0) {
+        if (parser.eval(cmd, io_chain_t{io_buffer}, SUBST) == 0) {
             subcommand_status = proc_get_last_status();
         }
 
diff --git a/src/fish_tests.cpp b/src/fish_tests.cpp
index df66fd4b5..1760944a7 100644
--- a/src/fish_tests.cpp
+++ b/src/fish_tests.cpp
@@ -920,7 +920,7 @@ static void test_parser() {
 
 static void test_1_cancellation(const wchar_t *src) {
     shared_ptr<io_buffer_t> out_buff(io_buffer_t::create(STDOUT_FILENO, io_chain_t()));
-    const io_chain_t io_chain(out_buff);
+    const io_chain_t io_chain{out_buff};
     pthread_t thread = pthread_self();
     double delay = 0.25 /* seconds */;
     iothread_perform([=]() {
diff --git a/src/io.cpp b/src/io.cpp
index 2f8fa32af..5cc0b733c 100644
--- a/src/io.cpp
+++ b/src/io.cpp
@@ -120,15 +120,15 @@ void io_chain_t::remove(const shared_ptr<const io_data_t> &element) {
     }
 }
 
-void io_chain_t::push_back(const shared_ptr<io_data_t> &element) {
+void io_chain_t::push_back(shared_ptr<io_data_t> element) {
     // Ensure we never push back NULL.
-    assert(element.get() != NULL);
-    std::vector<shared_ptr<io_data_t> >::push_back(element);
+    assert(element.get() != nullptr);
+    std::vector<shared_ptr<io_data_t> >::push_back(std::move(element));
 }
 
-void io_chain_t::push_front(const shared_ptr<io_data_t> &element) {
-    assert(element.get() != NULL);
-    this->insert(this->begin(), element);
+void io_chain_t::push_front(shared_ptr<io_data_t> element) {
+    assert(element.get() != nullptr);
+    this->insert(this->begin(), std::move(element));
 }
 
 void io_chain_t::append(const io_chain_t &chain) {
@@ -253,8 +253,3 @@ shared_ptr<const io_data_t> io_chain_get(const io_chain_t &src, int fd) {
 }
 
 shared_ptr<io_data_t> io_chain_get(io_chain_t &src, int fd) { return src.get_io_for_fd(fd); }
-
-io_chain_t::io_chain_t(const shared_ptr<io_data_t> &data)
-    : std::vector<shared_ptr<io_data_t> >(1, data) {}
-
-io_chain_t::io_chain_t() : std::vector<shared_ptr<io_data_t> >() {}
diff --git a/src/io.h b/src/io.h
index cee99ccab..161ec5941 100644
--- a/src/io.h
+++ b/src/io.h
@@ -270,14 +270,13 @@ class io_buffer_t : public io_pipe_t {
                                           size_t buffer_limit = 0);
 };
 
-class io_chain_t : public std::vector<shared_ptr<io_data_t> > {
+class io_chain_t : public std::vector<shared_ptr<io_data_t>> {
    public:
-    io_chain_t();
-    explicit io_chain_t(const shared_ptr<io_data_t> &);
+    using std::vector<shared_ptr<io_data_t>>::vector;
 
     void remove(const shared_ptr<const io_data_t> &element);
-    void push_back(const shared_ptr<io_data_t> &element);
-    void push_front(const shared_ptr<io_data_t> &element);
+    void push_back(shared_ptr<io_data_t> element);
+    void push_front(shared_ptr<io_data_t> element);
     void append(const io_chain_t &chain);
 
     shared_ptr<const io_data_t> get_io_for_fd(int fd) const;