diff --git a/doc_src/cmds/source.rst b/doc_src/cmds/source.rst
index d995c6a84..24f83b1bf 100644
--- a/doc_src/cmds/source.rst
+++ b/doc_src/cmds/source.rst
@@ -20,7 +20,7 @@ Description
 
 fish will search the working directory to resolve relative paths but will not search :envvar:`PATH` .
 
-If no file is specified and stdin is not the terminal, or if the file name ``-`` is used, stdin will be read.
+If no file is specified and a file or pipeline is connected to standard input, or if the file name ``-`` is used, ``source`` will read from standard input. If no file is specified and there is no redirected file or pipeline on standard input, an error will be printed.
 
 The exit status of ``source`` is the exit status of the last job to execute. If something goes wrong while opening or reading the file, ``source`` exits with a non-zero status.