diff --git a/test/Makefile.am b/test/Makefile.am
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -1,6 +1,7 @@
 EXTRA_DIST += \
 	test/CMakeLists.txt \
-        test/min_cost_flow_test.lgf
+        test/min_cost_flow_test.lgf \
+        test/preflow_graph.lgf
 
 noinst_HEADERS += \
 	test/graph_test.h \
@@ -23,6 +24,7 @@
 	test/max_matching_test \
         test/random_test \
         test/path_test \
+        test/preflow_test \
         test/suurballe_test \
         test/test_tools_fail \
         test/test_tools_pass \
@@ -47,6 +49,7 @@
 test_maps_test_SOURCES = test/maps_test.cc
 test_max_matching_test_SOURCES = test/max_matching_test.cc
 test_path_test_SOURCES = test/path_test.cc
+test_preflow_test_SOURCES = test/preflow_test.cc
 test_suurballe_test_SOURCES = test/suurballe_test.cc
 test_random_test_SOURCES = test/random_test.cc
 test_test_tools_fail_SOURCES = test/test_tools_fail.cc