diff --git a/src/tl/tl/tlInclude.cc b/src/tl/tl/tlInclude.cc
index 53a5a6dc1..e247ab9f3 100644
--- a/src/tl/tl/tlInclude.cc
+++ b/src/tl/tl/tlInclude.cc
@@ -134,7 +134,11 @@ IncludeExpander::to_string () const
     tl_assert (m_sections.begin ()->second.second == 0);
 
     std::string fn = m_sections.begin ()->second.first;
-    return tl::to_word_or_quoted_string (fn, valid_fn_chars);
+    if (! fn.empty () && fn.front () == '@') {
+      return tl::to_quoted_string (fn);
+    } else {
+      return fn;
+    }
 
   } else {
 
@@ -166,7 +170,9 @@ IncludeExpander::from_string (const std::string &s)
 
     ex.read_quoted (ie.m_sections [1].first);
 
-  } else if (ex.test ("@")) {
+  } else if (*ex == '@') {
+
+    ++ex;
 
     while (! ex.at_end ()) {
 
diff --git a/src/tl/unit_tests/tlIncludeTests.cc b/src/tl/unit_tests/tlIncludeTests.cc
index da681c43e..8ed1651fd 100644
--- a/src/tl/unit_tests/tlIncludeTests.cc
+++ b/src/tl/unit_tests/tlIncludeTests.cc
@@ -108,3 +108,31 @@ TEST(4_multi_include_interpolate)
   EXPECT_EQ (ie.translate_to_original (6).second, 3);
 }
 
+TEST(5_issue946)
+{
+  std::string fn = tl::testdata () + "/tl/x_inc4.txt";
+
+  std::string et;
+  tl::IncludeExpander ie = tl::IncludeExpander::expand (fn, tl::InputStream (fn).read_all (), et);
+  EXPECT_EQ (et, "A line\nincluded.4\nAnother line\n");
+
+  EXPECT_EQ (np (ie.to_string ()), np ("@1*" + tl::testdata () + "/tl/x_inc4.txt*0;2*'" + tl::testdata () + "/tl/inc 4.txt'*-1;3*" + tl::testdata () + "/tl/x_inc4.txt*0;"));
+  EXPECT_EQ (tl::IncludeExpander::from_string (ie.to_string ()).to_string (), ie.to_string ());
+
+  EXPECT_EQ (ie.translate_to_original (1).first, fn);
+  EXPECT_EQ (ie.translate_to_original (1).second, 1);
+  EXPECT_EQ (np (ie.translate_to_original (2).first), np (tl::testdata () + "/tl/inc 4.txt"));
+  EXPECT_EQ (ie.translate_to_original (2).second, 1);
+  EXPECT_EQ (ie.translate_to_original (3).first, fn);
+  EXPECT_EQ (ie.translate_to_original (3).second, 3);
+
+  fn = tl::testdata () + "/tl/inc 4.txt";
+
+  et.clear ();
+  ie = tl::IncludeExpander::expand (fn, tl::InputStream (fn).read_all (), et);
+  EXPECT_EQ (et, "included.4\n");
+
+  //  no quotes here so this string can be used as the original file name if there is no include
+  EXPECT_EQ (np (ie.to_string ()), np (tl::testdata () + "/tl/inc 4.txt"));
+}
+
diff --git a/testdata/tl/inc 4.txt b/testdata/tl/inc 4.txt
new file mode 100644
index 000000000..710f3fd3d
--- /dev/null
+++ b/testdata/tl/inc 4.txt	
@@ -0,0 +1 @@
+included.4
diff --git a/testdata/tl/x_inc4.txt b/testdata/tl/x_inc4.txt
new file mode 100644
index 000000000..954d8ff6f
--- /dev/null
+++ b/testdata/tl/x_inc4.txt
@@ -0,0 +1,3 @@
+A line
+# %include 'inc 4.txt'
+Another line