Index: pam_yubico-2.10/configure.ac
===================================================================
--- pam_yubico-2.10.orig/configure.ac
+++ pam_yubico-2.10/configure.ac
@@ -37,7 +37,10 @@ AC_PROG_LIBTOOL
 
 AC_CHECK_HEADERS([security/pam_appl.h], [],
   [AC_MSG_ERROR([[PAM header files not found, install libpam-dev.]])])
-AC_CHECK_HEADERS([security/pam_modules.h security/_pam_macros.h security/pam_modutil.h], [], [],
+AC_CHECK_HEADERS([security/pam_modutil.h], [], [],
+  [#include <security/pam_appl.h>
+   #include <unistd.h>])
+AC_CHECK_HEADERS([security/pam_modules.h security/_pam_macros.h], [], [],
   [#include <security/pam_appl.h>])
 
 AC_CHECK_LIB([pam], [pam_start])
Index: pam_yubico-2.10/drop_privs.c
===================================================================
--- pam_yubico-2.10.orig/drop_privs.c
+++ pam_yubico-2.10/drop_privs.c
@@ -47,6 +47,7 @@
 
 #ifdef HAVE_PAM_MODUTIL_DROP_PRIV
 #ifdef HAVE_SECURITY_PAM_MODUTIL_H
+#include <unistd.h>
 #include <security/pam_modutil.h>
 #endif /* HAVE_SECURITY_PAM_MODUTIL_H */
 #else