diff --git a/malloc/obstack.c b/malloc/obstack.c
index 2e50397150..e5c0c40de4 100644
--- a/malloc/obstack.c
+++ b/malloc/obstack.c
@@ -46,6 +46,9 @@
 #endif
 #endif
 
+#if defined _LIBC && defined USE_IN_LIBIO
+# include <wchar.h>
+#endif
 
 #ifndef ELIDE_CODE
 
diff --git a/misc/getpass.c b/misc/getpass.c
index c392221f67..e5483f9e50 100644
--- a/misc/getpass.c
+++ b/misc/getpass.c
@@ -22,6 +22,7 @@
 #include <unistd.h>
 
 #ifdef USE_IN_LIBIO
+# include <wchar.h>
 # define flockfile(s) _IO_flockfile (s)
 # define funlockfile(s) _IO_funlockfile (s)
 #endif