diff --git a/aclocal.m4 b/aclocal.m4
index b5b33b2..e3beb3b 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -20,6 +20,139 @@ You have another version of autoconf.  It may work, but is not guaranteed to.
 If you have problems, you may need to regenerate the build system entirely.
 To do so, use the procedure documented by the package, typically 'autoreconf'.])])
 
+dnl AM_PATH_CHECK([MINIMUM-VERSION, [ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND]]])
+dnl Test for check, and define CHECK_CFLAGS and CHECK_LIBS
+dnl
+
+AC_DEFUN([AM_PATH_CHECK],
+[
+  AC_MSG_WARN([A@&t@M_PATH_CHECK() is deprecated])
+  AC_MSG_WARN([[use P@&t@KG_CHECK_MODULES([CHECK], [check >= 0.9.4]) instead]])
+  AC_ARG_WITH([check],
+  [  --with-check=PATH       prefix where check is installed [default=auto]])
+ 
+  min_check_version=ifelse([$1], ,0.8.2,$1)
+
+  AC_MSG_CHECKING(for check - version >= $min_check_version)
+
+  if test x$with_check = xno; then
+    AC_MSG_RESULT(disabled)
+    ifelse([$3], , AC_MSG_ERROR([disabling check is not supported]), [$3])
+  else
+    if test "x$with_check" != x; then
+      CHECK_CFLAGS="-I$with_check/include"
+      CHECK_LIBS="-L$with_check/lib -lcheck"
+    else
+      CHECK_CFLAGS=""
+      CHECK_LIBS="-lcheck"
+    fi
+
+    ac_save_CFLAGS="$CFLAGS"
+    ac_save_LIBS="$LIBS"
+
+    CFLAGS="$CFLAGS $CHECK_CFLAGS"
+    LIBS="$CHECK_LIBS $LIBS"
+
+    rm -f conf.check-test
+    AC_COMPILE_IFELSE([AC_LANG_SOURCE([AC_INCLUDES_DEFAULT([])
+#include <check.h>
+
+int main ()
+{
+  int major, minor, micro;
+  char *tmp_version;
+
+  system ("touch conf.check-test");
+
+  /* HP/UX 9 (%@#!) writes to sscanf strings */
+  tmp_version = strdup("$min_check_version");
+  if (sscanf(tmp_version, "%d.%d.%d", &major, &minor, &micro) != 3) {
+     printf("%s, bad version string\n", "$min_check_version");
+     return 1;
+   }
+    
+  if ((CHECK_MAJOR_VERSION != check_major_version) ||
+      (CHECK_MINOR_VERSION != check_minor_version) ||
+      (CHECK_MICRO_VERSION != check_micro_version))
+    {
+      printf("\n*** The check header file (version %d.%d.%d) does not match\n",
+	     CHECK_MAJOR_VERSION, CHECK_MINOR_VERSION, CHECK_MICRO_VERSION);
+      printf("*** the check library (version %d.%d.%d).\n",
+	     check_major_version, check_minor_version, check_micro_version);
+      return 1;
+    }
+
+  if ((check_major_version > major) ||
+      ((check_major_version == major) && (check_minor_version > minor)) ||
+      ((check_major_version == major) && (check_minor_version == minor) && (check_micro_version >= micro)))
+    {
+      return 0;
+    }
+  else
+    {
+      printf("\n*** An old version of check (%d.%d.%d) was found.\n",
+             check_major_version, check_minor_version, check_micro_version);
+      printf("*** You need a version of check being at least %d.%d.%d.\n", major, minor, micro);
+      printf("***\n"); 
+      printf("*** If you have already installed a sufficiently new version, this error\n");
+      printf("*** probably means that the wrong copy of the check library and header\n");
+      printf("*** file is being found. Rerun configure with the --with-check=PATH option\n");
+      printf("*** to specify the prefix where the correct version was installed.\n");
+    }
+
+  return 1;
+}
+])],, no_check=yes, [echo $ac_n "cross compiling; assumed OK... $ac_c"])
+
+    CFLAGS="$ac_save_CFLAGS"
+    LIBS="$ac_save_LIBS"
+
+    if test "x$no_check" = x ; then
+      AC_MSG_RESULT(yes)
+      ifelse([$2], , :, [$2])
+    else
+      AC_MSG_RESULT(no)
+      if test -f conf.check-test ; then
+        :
+      else
+        echo "*** Could not run check test program, checking why..."
+        CFLAGS="$CFLAGS $CHECK_CFLAGS"
+        LIBS="$CHECK_LIBS $LIBS"
+        AC_TRY_LINK([
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <check.h>
+], ,  [ echo "*** The test program compiled, but did not run. This usually means"
+        echo "*** that the run-time linker is not finding check. You'll need to set your"
+        echo "*** LD_LIBRARY_PATH environment variable, or edit /etc/ld.so.conf to point"
+        echo "*** to the installed location  Also, make sure you have run ldconfig if that"
+        echo "*** is required on your system"
+	echo "***"
+        echo "*** If you have an old version installed, it is best to remove it, although"
+        echo "*** you may also be able to get things to work by modifying LD_LIBRARY_PATH"],
+      [ echo "*** The test program failed to compile or link. See the file config.log for"
+        echo "*** the exact error that occured." ])
+      
+        CFLAGS="$ac_save_CFLAGS"
+        LIBS="$ac_save_LIBS"
+      fi
+
+      CHECK_CFLAGS=""
+      CHECK_LIBS=""
+
+      rm -f conf.check-test
+      ifelse([$3], , AC_MSG_ERROR([check not found]), [$3])
+    fi
+
+    AC_SUBST(CHECK_CFLAGS)
+    AC_SUBST(CHECK_LIBS)
+
+    rm -f conf.check-test
+
+  fi
+])
+
 # libtool.m4 - Configure libtool for the host system. -*-Autoconf-*-
 #
 #   Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2003, 2004, 2005,
diff --git a/config.status b/config.status
index 393cca7..43b8a69 100755
--- a/config.status
+++ b/config.status
@@ -821,6 +821,10 @@ S["DEPS_CFLAGS"]="-D_THREAD_SAFE -I/opt/local/include "
 S["PKG_CONFIG_LIBDIR"]=""
 S["PKG_CONFIG_PATH"]=""
 S["PKG_CONFIG"]="/opt/local/bin/pkg-config"
+S["HAVE_CHECK_FALSE"]=""
+S["HAVE_CHECK_TRUE"]="#"
+S["CHECK_LIBS"]=""
+S["CHECK_CFLAGS"]=""
 S["CPP"]="gcc -E"
 S["OTOOL64"]=":"
 S["OTOOL"]="otool"
diff --git a/configure.ac b/configure.ac
index cc8471c..c558ce1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,8 +1,16 @@
 AC_INIT([r3], 1.0)
 AC_CONFIG_HEADERS(config.h)
+AC_CONFIG_MACRO_DIR([m4])
 AM_INIT_AUTOMAKE
 LT_INIT
 AC_PROG_CC
+
+# AM_PATH_CHECK()
+AM_PATH_CHECK(,[have_check="yes"],
+  AC_MSG_WARN([Check not found; cannot run unit tests!])
+  [have_check="no"])
+AM_CONDITIONAL(HAVE_CHECK, test x"$have_check" = "xyes")
+
 PKG_PROG_PKG_CONFIG
 PKG_CHECK_MODULES(DEPS, [libpcre check])
 AC_SUBST(DEPS_CFLAGS)
diff --git a/src/edge.c b/src/edge.c
index cccd531..ea71ad7 100644
--- a/src/edge.c
+++ b/src/edge.c
@@ -17,6 +17,7 @@
 
 // Judy array
 // #include <Judy.h>
+#include <config.h>
 
 #include "r3_define.h"
 #include "r3_str.h"
diff --git a/src/node.c b/src/node.c
index 100bd0e..288192b 100644
--- a/src/node.c
+++ b/src/node.c
@@ -1,3 +1,4 @@
+#include <config.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tests/Makefile.am b/tests/Makefile.am
index d2f1365..a25f7c3 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -1,5 +1,14 @@
-bin_PROGRAMS=test_tree
-test_tree_SOURCES=test_tree.c
-test_tree_LDADD=$(DEPS_LIBS) -L$(top_builddir)/src -lcheck -lr3
+# INCLUDES                    = @CHECK_CFLAGS@
+if HAVE_CHECK
+TESTS                       = check_tree
+else
+TESTS                       =
+endif
+# noinst_PROGRAMS             = $(TESTS)
+check_PROGRAMS = $(TESTS)
+check_tree_SOURCES = check_tree.c
+check_tree_LDADD=$(DEPS_LIBS) -L$(top_builddir)/src -lcheck -lr3
+check_tree_CFLAGS=$(DEPS_CFLAGS) @CHECK_CFLAGS@
 # AM_CFLAGS=$(DEPS_CFLAGS) -I$(top_builddir)/include
 AM_CFLAGS=$(DEPS_CFLAGS) -I$(top_builddir) -I$(top_builddir)/include
+CLEANFILES                  = check_tree.log
diff --git a/tests/test_tree.c b/tests/check_tree.c
similarity index 99%
rename from tests/test_tree.c
rename to tests/check_tree.c
index 930741d..f36e2af 100644
--- a/tests/test_tree.c
+++ b/tests/check_tree.c
@@ -1,3 +1,4 @@
+#include "config.h"
 #include <stdio.h>
 #include <check.h>
 #include <stdlib.h>