diff --git a/src/io.cpp b/src/io.cpp
index 443badeb7..21b98fc2f 100644
--- a/src/io.cpp
+++ b/src/io.cpp
@@ -222,21 +222,15 @@ void io_chain_t::append(const io_chain_t &chain) {
     this->insert(this->end(), chain.begin(), chain.end());
 }
 
-#if 0
-// This isn't used so the lint tools were complaining about its presence. I'm keeping it in the
-// source because it could be useful for debugging.
-void io_print(const io_chain_t &chain)
-{
-    if (chain.empty())
-    {
-        std::fwprintf(stderr, L"Empty chain %p\n", &chain);
+void io_chain_t::print() const {
+    if (this->empty()) {
+        std::fwprintf(stderr, L"Empty chain %p\n", this);
         return;
     }
 
-    std::fwprintf(stderr, L"Chain %p (%ld items):\n", &chain, (long)chain.size());
-    for (size_t i=0; i < chain.size(); i++)
-    {
-        const shared_ptr<io_data_t> &io = chain.at(i);
+    std::fwprintf(stderr, L"Chain %p (%ld items):\n", this, (long)this->size());
+    for (size_t i = 0; i < this->size(); i++) {
+        const auto &io = this->at(i);
         if (io.get() == nullptr)
         {
             std::fwprintf(stderr, L"\t(null)\n");
@@ -248,7 +242,6 @@ void io_print(const io_chain_t &chain)
         }
     }
 }
-#endif
 
 int move_fd_to_unused(int fd, const io_chain_t &io_chain, bool cloexec) {
     if (fd < 0 || io_chain.io_for_fd(fd).get() == nullptr) {
diff --git a/src/io.h b/src/io.h
index 5ea8287de..796caafc2 100644
--- a/src/io.h
+++ b/src/io.h
@@ -346,6 +346,9 @@ class io_chain_t : public std::vector<io_data_ref_t> {
     /// \return the last io redirection in the chain for the specified file descriptor, or nullptr
     /// if none.
     io_data_ref_t io_for_fd(int fd) const;
+
+    /// Output debugging information to stderr.
+    void print() const;
 };
 
 /// Helper type returned from making autoclose pipes.
@@ -436,9 +439,5 @@ struct io_streams_t {
     explicit io_streams_t(size_t read_limit) : out(read_limit), err(read_limit), stdin_fd(-1) {}
 };
 
-#if 0
-// Print debug information about the specified IO redirection chain to stderr.
-void io_print(const io_chain_t &chain);
-#endif
 
 #endif