diff --git a/src/libstore/derivations.cc b/src/libstore/derivations.cc
index 38a87240c..0c6ceb9f6 100644
--- a/src/libstore/derivations.cc
+++ b/src/libstore/derivations.cc
@@ -4,7 +4,7 @@
 #include "util.hh"
 #include "worker-protocol.hh"
 #include "fs-accessor.hh"
-
+#include "istringstream_nocopy.hh"
 
 namespace nix {
 
diff --git a/src/libstore/s3-binary-cache-store.cc b/src/libstore/s3-binary-cache-store.cc
index 5a8acfb50..3053f908c 100644
--- a/src/libstore/s3-binary-cache-store.cc
+++ b/src/libstore/s3-binary-cache-store.cc
@@ -7,6 +7,7 @@
 #include "globals.hh"
 #include "compression.hh"
 #include "download.hh"
+#include "istringstream_nocopy.hh"
 
 #include <aws/core/Aws.h>
 #include <aws/core/client/ClientConfiguration.h>
diff --git a/src/libutil/hash.cc b/src/libutil/hash.cc
index a8bbcf8c1..9f4afd93c 100644
--- a/src/libutil/hash.cc
+++ b/src/libutil/hash.cc
@@ -7,12 +7,12 @@
 #include "hash.hh"
 #include "archive.hh"
 #include "util.hh"
+#include "istringstream_nocopy.hh"
 
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 
-
 namespace nix {
 
 
diff --git a/src/libutil/istringstream_nocopy.hh b/src/libutil/istringstream_nocopy.hh
new file mode 100644
index 000000000..f7beac578
--- /dev/null
+++ b/src/libutil/istringstream_nocopy.hh
@@ -0,0 +1,92 @@
+/* This file provides a variant of std::istringstream that doesn't
+   copy its string argument. This is useful for large strings. The
+   caller must ensure that the string object is not destroyed while
+   it's referenced by this object. */
+
+#pragma once
+
+#include <string>
+#include <iostream>
+
+template <class CharT, class Traits = std::char_traits<CharT>, class Allocator = std::allocator<CharT>>
+class basic_istringbuf_nocopy : public std::basic_streambuf<CharT, Traits>
+{
+public:
+    typedef std::basic_string<CharT, Traits, Allocator> string_type;
+
+    typedef typename std::basic_streambuf<CharT, Traits>::off_type off_type;
+
+    typedef typename std::basic_streambuf<CharT, Traits>::pos_type pos_type;
+
+    typedef typename std::basic_streambuf<CharT, Traits>::int_type int_type;
+
+    typedef typename std::basic_streambuf<CharT, Traits>::traits_type traits_type;
+
+private:
+    const string_type & s;
+
+    off_type off;
+
+public:
+    basic_istringbuf_nocopy(const string_type & s) : s{s}, off{0}
+    {
+    }
+
+private:
+    pos_type seekoff(off_type off, std::ios_base::seekdir dir, std::ios_base::openmode which)
+    {
+        if (which & std::ios_base::in) {
+            this->off = dir == std::ios_base::beg
+                ? off
+                : (dir == std::ios_base::end
+                    ? s.size() + off
+                    : this->off + off);
+        }
+        return pos_type(this->off);
+    }
+
+    pos_type seekpos(pos_type pos, std::ios_base::openmode which)
+    {
+        return seekoff(pos, std::ios_base::beg, which);
+    }
+
+    std::streamsize showmanyc()
+    {
+        return s.size() - off;
+    }
+
+    int_type underflow()
+    {
+        if (typename string_type::size_type(off) == s.size())
+            return traits_type::eof();
+        return traits_type::to_int_type(s[off]);
+    }
+
+    int_type uflow()
+    {
+        if (typename string_type::size_type(off) == s.size())
+            return traits_type::eof();
+        return traits_type::to_int_type(s[off++]);
+    }
+
+    int_type pbackfail(int_type ch)
+    {
+        if (off == 0 || (ch != traits_type::eof() && ch != s[off - 1]))
+            return traits_type::eof();
+
+        return traits_type::to_int_type(s[--off]);
+    }
+
+};
+
+template <class CharT, class Traits = std::char_traits<CharT>, class Allocator = std::allocator<CharT>>
+class basic_istringstream_nocopy : public std::basic_iostream<CharT, Traits>
+{
+    typedef basic_istringbuf_nocopy<CharT, Traits, Allocator> buf_type;
+    buf_type buf;
+public:
+    basic_istringstream_nocopy(const typename buf_type::string_type & s) :
+        std::basic_iostream<CharT, Traits>(&buf), buf(s) {};
+};
+
+typedef basic_istringstream_nocopy<char> istringstream_nocopy;
diff --git a/src/libutil/util.hh b/src/libutil/util.hh
index 645289f67..0e6941e4a 100644
--- a/src/libutil/util.hh
+++ b/src/libutil/util.hh
@@ -451,92 +451,4 @@ struct ReceiveInterrupts
     { }
 };
 
-
-template <class CharT, class Traits = std::char_traits<CharT>, class Allocator = std::allocator<CharT>>
-class basic_istringbuf_nocopy : public std::basic_streambuf<CharT, Traits>
-{
-public:
-    typedef std::basic_string<CharT, Traits, Allocator> string_type;
-
-    typedef typename std::basic_streambuf<CharT, Traits>::off_type off_type;
-
-    typedef typename std::basic_streambuf<CharT, Traits>::pos_type pos_type;
-
-    typedef typename std::basic_streambuf<CharT, Traits>::int_type int_type;
-
-    typedef typename std::basic_streambuf<CharT, Traits>::traits_type traits_type;
-
-private:
-    const string_type & s;
-
-    off_type off;
-
-public:
-    basic_istringbuf_nocopy(const string_type & s) : s{s}, off{0}
-    {
-    }
-
-private:
-    pos_type seekoff(off_type off, std::ios_base::seekdir dir, std::ios_base::openmode which)
-    {
-        if (which & std::ios_base::in) {
-            this->off = dir == std::ios_base::beg
-                ? off
-                : (dir == std::ios_base::end
-                    ? s.size() + off
-                    : this->off + off);
-        }
-        return pos_type(this->off);
-    }
-
-    pos_type seekpos(pos_type pos, std::ios_base::openmode which)
-    {
-        return seekoff(pos, std::ios_base::beg, which);
-    }
-
-    std::streamsize showmanyc()
-    {
-        return s.size() - off;
-    }
-
-    int_type underflow()
-    {
-        if (typename string_type::size_type(off) == s.size())
-            return traits_type::eof();
-        return traits_type::to_int_type(s[off]);
-    }
-
-    int_type uflow()
-    {
-        if (typename string_type::size_type(off) == s.size())
-            return traits_type::eof();
-        return traits_type::to_int_type(s[off++]);
-    }
-
-    int_type pbackfail(int_type ch)
-    {
-        if (off == 0 || (ch != traits_type::eof() && ch != s[off - 1]))
-            return traits_type::eof();
-
-        return traits_type::to_int_type(s[--off]);
-    }
-
-};
-
-template <class CharT, class Traits = std::char_traits<CharT>, class Allocator = std::allocator<CharT>>
-class basic_istringstream_nocopy : public std::basic_iostream<CharT, Traits>
-{
-    typedef basic_istringbuf_nocopy<CharT, Traits, Allocator> buf_type;
-    buf_type buf;
-public:
-    basic_istringstream_nocopy(const typename buf_type::string_type & s) :
-        std::basic_iostream<CharT, Traits>(&buf), buf(s) {};
-};
-
-/* A variant of std::istringstream that doesn't its string
-   argument. This is useful for large strings. The caller must ensure
-   that the string object is not destroyed while it's referenced by
-   this object. */
-typedef basic_istringstream_nocopy<char> istringstream_nocopy;
-
 }