diff --git a/Makefile.am b/Makefile.am
index c1053e0..2da357e 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -12,7 +12,7 @@ noinst_HEADERS = snappy-internal.h snappy-stubs-internal.h snappy-test.h
 snappy_unittest_CPPFLAGS = $(gflags_CFLAGS) $(GTEST_CPPFLAGS)
 snappy_unittest_SOURCES = snappy_unittest.cc snappy-test.cc
 snappy_unittest_LDFLAGS = $(GTEST_LDFLAGS)
-snappy_unittest_LDADD = libsnappy.la $(gflags_LIBS) $(GTEST_LIBS)
+snappy_unittest_LDADD = libsnappy.la $(UNITTEST_LIBS) $(gflags_LIBS) $(GTEST_LIBS)
 TESTS = snappy_unittest
 noinst_PROGRAMS = $(TESTS)
 
diff --git a/configure.ac b/configure.ac
index cf3b48c..1351b76 100644
--- a/configure.ac
+++ b/configure.ac
@@ -79,11 +79,25 @@ fi
 
 # Other compression libraries; the unit test can use these for comparison
 # if they are available. If they are not found, just ignore.
-AC_CHECK_LIB([z], [zlibVersion],, [true])
-AC_CHECK_LIB([lzo2], [lzo1x_1_15_compress],, [true])
-AC_CHECK_LIB([lzf], [lzf_compress],, [true])
-AC_CHECK_LIB([fastlz], [fastlz_compress],, [true])
-AC_CHECK_LIB([quicklz], [qlz_compress],, [true])
+UNITTEST_LIBS=""
+AC_DEFUN([CHECK_EXT_COMPRESSION_LIB], [
+  AH_CHECK_LIB([$1])
+  AC_CHECK_LIB(
+    [$1],
+    [$2],
+    [
+      AC_DEFINE_UNQUOTED(AS_TR_CPP(HAVE_LIB$1))
+      UNITTEST_LIBS="-l$1 $UNITTEST_LIBS"
+    ],
+    [true]
+  )
+])
+CHECK_EXT_COMPRESSION_LIB([z], [zlibVersion])
+CHECK_EXT_COMPRESSION_LIB([lzo2], [lzo1x_1_15_compress])
+CHECK_EXT_COMPRESSION_LIB([lzf], [lzf_compress])
+CHECK_EXT_COMPRESSION_LIB([fastlz], [fastlz_compress])
+CHECK_EXT_COMPRESSION_LIB([quicklz], [qlz_compress])
+AC_SUBST([UNITTEST_LIBS])
 
 # These are used by snappy-stubs-public.h.in.
 if test "$ac_cv_header_stdint_h" = "yes"; then