diff --git a/configure.ac b/configure.ac
index fadf0c93..448998f0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -44,14 +44,32 @@ AC_PROG_MAKE_SET
 PKG_PROG_PKG_CONFIG([0.20])
 
 # Checks for libraries.
+
+# zlib
 PKG_CHECK_MODULES([ZLIB], [zlib >= 1.2.3])
 LIBS=$ZLIB_LIBS $LIBS
 CFLAGS=$CFLAGS $ZLIB_CFLAGS
 
-AC_CHECK_LIB([cunit], [CU_initialize_registry],
-             [have_cunit=yes], [have_cunit=no])
+# cunit
+PKG_CHECK_MODULES([CUNIT], [cunit >= 2.1], [have_cunit=yes], [have_cunit=no])
+# If pkg-config does not find cunit, check it using AC_CHECK_LIB.  We
+# do this because Debian (Ubuntu) lacks pkg-config file for cunit.
+if test "x${have_cunit}" = "xno"; then
+  AC_MSG_WARN([${CUNIT_PKG_ERRORS}])
+  AC_CHECK_LIB([cunit], [CU_initialize_registry],
+               [have_cunit=yes], [have_cunit=no])
+  if test "x${have_cunit}" = "xyes"; then
+    CUNIT_LIBS="-lcunit"
+    CUNIT_CFLAGS=""
+    AC_SUBST([CUNIT_LIBS])
+    AC_SUBST([CUNIT_CFLAGS])
+  fi
+fi
 AM_CONDITIONAL([HAVE_CUNIT], [ test "x${have_cunit}" = "xyes" ])
 
+# openssl (for examples)
+PKG_CHECK_MODULES([OPENSSL], [openssl >= 1.0.0])
+
 # Checks for header files.
 AC_CHECK_HEADERS([ \
   arpa/inet.h \
diff --git a/examples/Makefile.am b/examples/Makefile.am
index 2017f8d6..480c455d 100644
--- a/examples/Makefile.am
+++ b/examples/Makefile.am
@@ -22,8 +22,9 @@
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 AM_CFLAGS = -Wall
-AM_CPPFLAGS = -I$(srcdir)/../lib/includes -I$(builddir)/../lib/includes `pkg-config --cflags libssl libcrypto`
-AM_LDFLAGS = `pkg-config --libs libssl libcrypto`
+AM_CPPFLAGS = -I$(srcdir)/../lib/includes -I$(builddir)/../lib/includes \
+	@OPENSSL_CFLAGS@
+AM_LDFLAGS = @OPENSSL_LIBS@
 LDADD = $(top_builddir)/lib/libspdylay.la
 
 bin_PROGRAMS = spdycat spdyd
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 18b4a779..0e247b9b 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -36,8 +36,9 @@ HFILES = spdylay_pq_test.h spdylay_map_test.h spdylay_queue_test.h \
 main_SOURCES = $(HFILES) $(OBJECTS)
 
 main_LDADD = ${top_builddir}/lib/libspdylay.la
-main_LDFLAGS = -static -lcunit -lncurses
-AM_CFLAGS = -Wall -g -O2 -I${top_srcdir}/lib -I${top_srcdir}/lib/includes
+main_LDFLAGS = -static @CUNIT_LIBS@ -lncurses
+AM_CFLAGS = -Wall -g -O2 -I${top_srcdir}/lib -I${top_srcdir}/lib/includes \
+	@CUNIT_CFLAGS@
 
 TESTS = main