diff --git a/test/Makefile.am b/test/Makefile.am
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -12,6 +12,7 @@
 	test/dfs_test \
 	test/digraph_test \
         test/dim_test \
+	test/error_test \
 	test/graph_test \
 	test/kruskal_test \
         test/maps_test \
@@ -28,7 +29,7 @@
 test_dfs_test_SOURCES = test/dfs_test.cc
 test_digraph_test_SOURCES = test/digraph_test.cc
 test_dim_test_SOURCES = test/dim_test.cc
-#test_error_test_SOURCES = test/error_test.cc
+test_error_test_SOURCES = test/error_test.cc
 test_graph_test_SOURCES = test/graph_test.cc
 # test_heap_test_SOURCES = test/heap_test.cc
 test_kruskal_test_SOURCES = test/kruskal_test.cc