diff --git a/configure.ac b/configure.ac
index bc89a44f3..e1cd652db 100644
--- a/configure.ac
+++ b/configure.ac
@@ -399,6 +399,10 @@ if test "$enable_logind" = "yes"; then
 fi
 AM_CONDITIONAL(ENABLE_LOGIND, test "x$enable_logind" != "xno")
 
+AC_SUBST(LIBA2I)
+AC_CHECK_LIB(a2i, str2si, [LIBA2I=-la2i],
+	[AC_MSG_ERROR([str2si() not found])])
+
 AC_SUBST(LIBCRYPT)
 AC_CHECK_LIB(crypt, crypt, [LIBCRYPT=-lcrypt],
 	[AC_MSG_ERROR([crypt() not found])])
diff --git a/lib/Makefile.am b/lib/Makefile.am
index a281bdf45..c3a690dab 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -19,7 +19,7 @@ libshadow_la_CPPFLAGS += -DVENDORDIR=\"$(VENDORDIR)\"
 endif
 
 libshadow_la_CPPFLAGS += -I$(top_srcdir)
-libshadow_la_CFLAGS = $(LIBBSD_CFLAGS) $(LIBCRYPT_PAM) $(LIBSYSTEMD)
+libshadow_la_CFLAGS = $(LIBBSD_CFLAGS) $(LIBA2I) $(LIBCRYPT_PAM) $(LIBSYSTEMD)
 libshadow_la_LIBADD = $(LIBADD_DLOPEN)
 
 libshadow_la_SOURCES = \
diff --git a/libsubid/Makefile.am b/libsubid/Makefile.am
index b6488e779..1e4139b70 100644
--- a/libsubid/Makefile.am
+++ b/libsubid/Makefile.am
@@ -5,6 +5,7 @@ libsubid_la_LDFLAGS = -version-info @LIBSUBID_ABI_MAJOR@ -export-symbols-regex '
 pkginclude_HEADERS = subid.h
 
 MISCLIBS = \
+	$(LIBA2I) \
 	$(LIBAUDIT) \
 	$(LIBSELINUX) \
 	$(LIBSEMANAGE) \
diff --git a/src/Makefile.am b/src/Makefile.am
index d4e6f3ab7..0c535dc32 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -83,7 +83,9 @@ if WITH_TCB
 shadowsgidubins = passwd
 endif
 
-LDADD          = $(INTLLIBS) \
+LDADD          = \
+		 $(LIBA2I) \
+		 $(INTLLIBS) \
 		 $(top_builddir)/lib/libshadow.la \
 		 $(LIBTCB)