diff --git a/Makefile.am b/Makefile.am
index 92365ae33..afee47c5b 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -40,13 +40,13 @@ test_kex_SOURCES = src/kex/test_kex.c
 test_kex_CPPFLAGS = -I./include
 test_kex_CPPFLAGS += $(AM_CPPFLAGS)
 if USE_OPENSSL
-test_kex_LDADD += -lcrypto
+test_kex_LDADD += -L$(OPENSSL_DIR)/lib  -lcrypto
 endif
 if USE_MCBITS
-test_kex_LDADD += -lsodium
+test_kex_LDADD += -L${SODIUM_DIR}/lib -lsodium
 endif
 if USE_SIDH_IQC
-test_kex_LDADD += -lgmp
+test_kex_LDADD += -L$(GMP_DIR)/lib -lgmp
 endif
 
 test_aes_LDADD =  liboqs.la -lm
@@ -56,7 +56,7 @@ test_aes_CPPFLAGS += $(AM_CPPFLAGS)
 
 
 if USE_OPENSSL
-test_aes_LDADD += -lcrypto
+test_aes_LDADD += -L$(OPENSSL_DIR)/lib -lcrypto
 endif
 
 test_rand_SOURCES = src/crypto/rand/test_rand.c
@@ -65,7 +65,7 @@ test_rand_CPPFLAGS = -Iinclude -Isrc/crypto/rand_urandom_aesctr/
 test_rand_CPPFLAGS += $(AM_CPPFLAGS)
 test_rand_LDADD = liboqs.la
 if USE_OPENSSL
-test_rand_LDADD += -lcrypto
+test_rand_LDADD += -L$(OPENSSL_DIR)/lib -lcrypto
 else
 if USE_AES_NI
 test_rand_CPPFLAGS += -maes -msse2
diff --git a/configure.ac b/configure.ac
index 4dd178fe5..f54a27954 100644
--- a/configure.ac
+++ b/configure.ac
@@ -85,37 +85,9 @@ AC_CANONICAL_HOST
 # specifically based on the host
 case $host_os in
   darwin* )
-        AC_ARG_WITH(
-          [openssl-dir],
-          AS_HELP_STRING([--with-openssl-dir=dir],[openssl dir used locally (default /usr/local/opt/openssl).]),
-          [AC_DEFINE_UNQUOTED(OPENSSLDIR, [$withval], [OPENSSL DIR used locally])
-           AC_SUBST(OPENSSL_DIR, [$withval])],
-          [AC_SUBST(OPENSSL_DIR, /usr/local/opt/openssl)]
-        )
-        AC_ARG_WITH(
-          [gmp-dir],
-          AS_HELP_STRING([--with-gmp-dir=dir],[gmp dir used locally (default /usr/local/opt/).]),
-          [AC_DEFINE_UNQUOTED(GMPDIR, [$withval], [GMP DIR used locally])
-           AC_SUBST(GMP_DIR, [$withval])],
-          [AC_SUBST(GMP_DIR, /usr/local)]
-        )
         AM_CONDITIONAL([ON_DARWIN], [test xtrue = xtrue])
         ;;
   linux*)
-        AC_ARG_WITH(
-          [openssl-dir],
-          AS_HELP_STRING([--with-openssl-dir=dir],[openssl dir used locally (default /usr).]),
-          [AC_DEFINE_UNQUOTED(OPENSSLDIR, [$withval], [OPENSSL DIR used locally])
-           AC_SUBST(OPENSSL_DIR, [$withval])],
-          [AC_SUBST(OPENSSL_DIR, /usr)]
-        )
-        AC_ARG_WITH(
-          [gmp-dir],
-          AS_HELP_STRING([--with-gmp-dir=dir],[gmp dir used locally (default /usr).]),
-          [AC_DEFINE_UNQUOTED(GMPDIR, [$withval], [GMP DIR used locally])
-           AC_SUBST(GMP_DIR, [$withval])],
-          [AC_SUBST(GMP_DIR, /usr)]
-        )
         if test x"${ac_cv_sizeof_size_t}" = x"8";then
           AM_CPPFLAGS=${AM_CPPFLAGS}" -DSIDH_ASM -march=x86-64"
         fi
@@ -127,6 +99,28 @@ case $host_os in
         ;;
 esac
 
+AC_ARG_WITH(
+  [openssl-dir],
+  AS_HELP_STRING([--with-openssl-dir=dir],[openssl dir used locally (default /usr).]),
+  [AC_DEFINE_UNQUOTED(OPENSSLDIR, [$withval], [OPENSSL DIR used locally])
+   AC_SUBST(OPENSSL_DIR, [$withval])],
+  [AC_SUBST(OPENSSL_DIR, /usr)]
+)
+AC_ARG_WITH(
+  [gmp-dir],
+  AS_HELP_STRING([--with-gmp-dir=dir],[gmp dir used locally (default /usr).]),
+  [AC_DEFINE_UNQUOTED(GMPDIR, [$withval], [GMP DIR used locally])
+   AC_SUBST(GMP_DIR, [$withval])],
+  [AC_SUBST(GMP_DIR, /usr)]
+)
+AC_ARG_WITH(
+  [sodium-dir],
+  AS_HELP_STRING([--with-sodium-dir=dir],[sodium dir used locally (default /usr).]),
+  [AC_DEFINE_UNQUOTED(SODIUMDIR, [$withval], [SODIUM DIR used locally])
+   AC_SUBST(SODIUM_DIR, [$withval])],
+  [AC_SUBST(SODIUM_DIR, /usr)]
+)
+
 SRCDIR=" src/common src/crypto/aes src/kex src/crypto/rand src/crypto/sha3"
 SRCDIR=${SRCDIR}" src/crypto/rand_urandom_aesctr src/crypto/rand_urandom_chacha20"
 SRCDIR=${SRCDIR}" src/kex_rlwe_bcns15/"
@@ -161,14 +155,12 @@ fi
 
 AC_SUBST(AM_CPPFLAGS)
 AC_SUBST(SRCDIR)
-AC_SUBST(OPENSSL_DIR)
 AC_SUBST(USE_OPENSSL)
 AC_SUBST(USE_AES_NI)
 AC_SUBST(USE_NTRU)
 AC_SUBST(USE_MCBITS)
 AC_SUBST(USE_SIDH_IQC)
 AC_SUBST(ON_DARWIN)
-AC_SUBST(GMP_DIR)
 
 
 AC_CONFIG_FILES([Makefile
diff --git a/src/kex_code_mcbits/Makefile.am b/src/kex_code_mcbits/Makefile.am
index 01bb5d1a7..2e29344b0 100644
--- a/src/kex_code_mcbits/Makefile.am
+++ b/src/kex_code_mcbits/Makefile.am
@@ -3,7 +3,7 @@ noinst_LTLIBRARIES = libmcbits.la
 
 libmcbits_la_SOURCES = external/operations.c kex_code_mcbits.c
 
-libmcbits_la_CPPFLAGS = -I../../include
+libmcbits_la_CPPFLAGS = -I../../include -I${SODIUM_DIR}/include
 
 libmcbits_la_CPPFLAGS += $(AM_CPPFLAGS)