diff --git a/Makefile.am b/Makefile.am
index ff56efe..db4fcfc 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -27,13 +27,13 @@ if JITTER
 rngd_SOURCES	+= rngd_jitter.c
 endif
 
-rngd_LDADD	= librngd.a -lsysfs $(LIBS) ${libp11_LIBS} ${libcurl_LIBS} ${libxml2_LIBS} ${openssl_LIBS} $(PTHREAD_LIBS)
+rngd_LDADD	= librngd.a -lsysfs $(LIBS) ${libp11_LIBS} ${libcrypto_LIBS} ${libcurl_LIBS} ${libxml2_LIBS} ${openssl_LIBS} $(PTHREAD_LIBS)
 
 if PKCS11 
 rngd_SOURCES	+= rngd_pkcs11.c
 endif
 
-rngd_CFLAGS	= ${pkcs11_CFLAGS} ${libp11_CFLAGS} ${libxml2_CFLAGS} ${openssl_CFLAGS} $(PTHREAD_CFLAGS)
+rngd_CFLAGS	= ${pkcs11_CFLAGS} ${libp11_CFLAGS} ${libcrypto_CFLAGS} ${libxml2_CFLAGS} ${openssl_CFLAGS} $(PTHREAD_CFLAGS)
 rngd_LDFLAGS	= $(PTHREAD_CFLAGS) 
 
 rngtest_SOURCES	= exits.h stats.h stats.c rngtest.c
diff --git a/configure.ac b/configure.ac
index 26b4806..5d4f270 100644
--- a/configure.ac
+++ b/configure.ac
@@ -102,6 +102,7 @@ AS_IF(
 	[ test "x$with_pkcs11" != "xno"],
 	[
 		PKG_CHECK_MODULES([libp11], [libp11], [], [AC_MSG_ERROR([libp11 is required])])
+		PKG_CHECK_MODULES([libcrypto], [libcrypto], [], [AC_MSG_ERROR([libcrypto is required])])
 		AC_DEFINE([HAVE_PKCS11],1,[Enable PKCS11])
 	]
 )