diff --git a/source/iostreams.tex b/source/iostreams.tex
index 5f837ac797..eeee3ee67b 100644
--- a/source/iostreams.tex
+++ b/source/iostreams.tex
@@ -10743,7 +10743,7 @@
 \indexlibraryctor{basic_spanstream}%
 \begin{itemdecl}
 explicit basic_spanstream(std::span<charT> s,
-                          ios_base::openmode which = ios_base::out | ios_bas::in);
+                          ios_base::openmode which = ios_base::out | ios_base::in);
 \end{itemdecl}
 
 \begin{itemdescr}