diff --git a/stdio-common/Makefile b/stdio-common/Makefile
index 16f8f1b..be58f0f 100644
--- a/stdio-common/Makefile
+++ b/stdio-common/Makefile
@@ -110,9 +110,9 @@ CFLAGS-siglist.c = $(fno-unit-at-a-time)
 # GNU extension.  The latter are needed, though, when internal headers
 # are used.  So made sure we see the installed headers first.
 CFLAGS-scanf15.c = -I../libio -I../stdlib -I../wcsmbs -I../time -I../string \
-		   -I../wctype
+		   -I../wctype -I$(common-objpfx)misc
 CFLAGS-scanf17.c = -I../libio -I../stdlib -I../wcsmbs -I../time -I../string \
-		   -I../wctype
+		   -I../wctype -I$(common-objpfx)misc
 
 # We know the test has a format string problem.
 CFLAGS-tst-sprintf.c = -Wno-format