diff --git a/unittest/formats/test_dump_custom.cpp b/unittest/formats/test_dump_custom.cpp
index e4787acd7f..7e441d7555 100644
--- a/unittest/formats/test_dump_custom.cpp
+++ b/unittest/formats/test_dump_custom.cpp
@@ -27,9 +27,10 @@ class DumpCustomTest : public MeltTest {
 TEST_F(DumpCustomTest, run1)
 {
     auto dump_file = "dump_custom_run1.melt";
+    auto fields = "id type proc procp1 mass x y z ix iy iz xs ys zs xu yu zu xsu ysu zsu vx vy vz fx fy fz";
 
     if (!verbose) ::testing::internal::CaptureStdout();
-    command(fmt::format("dump id all custom 1 {} id type x y vx fx", dump_file));
+    command(fmt::format("dump id all custom 1 {} {}", dump_file, fields));
     command("dump_modify id units yes");
     command("run 1");
     if (!verbose) ::testing::internal::GetCapturedStdout();
@@ -40,7 +41,99 @@ TEST_F(DumpCustomTest, run1)
     ASSERT_EQ(lines.size(), 84);
     ASSERT_STREQ(lines[6].c_str(), "ITEM: BOX BOUNDS pp pp pp");
     ASSERT_EQ(utils::split_words(lines[7]).size(), 2);
-    ASSERT_STREQ(lines[10].c_str(), "ITEM: ATOMS id type x y vx fx");
+    ASSERT_STREQ(lines[10].c_str(), fmt::format("ITEM: ATOMS {}", fields).c_str());
+    ASSERT_EQ(utils::split_words(lines[11]).size(), 26);
+    delete_file(dump_file);
+}
+
+TEST_F(DumpCustomTest, thresh_run0)
+{
+    auto dump_file = "dump_custom_thresh_run0.melt";
+    auto fields = "id type x y z";
+
+    if (!verbose) ::testing::internal::CaptureStdout();
+    command(fmt::format("dump id all custom 1 {} {}", dump_file, fields));
+    command("dump_modify id units yes thresh x < 1 thresh y < 1 thresh z < 1");
+    command("run 0");
+    if (!verbose) ::testing::internal::GetCapturedStdout();
+
+
+    ASSERT_FILE_EXISTS(dump_file);
+    auto lines = read_lines(dump_file);
+    ASSERT_EQ(lines.size(), 15);
+    ASSERT_STREQ(lines[6].c_str(), "ITEM: BOX BOUNDS pp pp pp");
+    ASSERT_EQ(utils::split_words(lines[7]).size(), 2);
+    ASSERT_STREQ(lines[10].c_str(), fmt::format("ITEM: ATOMS {}", fields).c_str());
+    ASSERT_EQ(utils::split_words(lines[11]).size(), 5);
+    delete_file(dump_file);
+}
+
+TEST_F(DumpCustomTest, compute_run0)
+{
+    auto dump_file = "dump_custom_compute_run0.melt";
+    auto fields = "id type x y z c_comp[1] c_comp[2] c_comp[3]";
+
+    if (!verbose) ::testing::internal::CaptureStdout();
+    command("compute comp all property/atom x y z");
+    command(fmt::format("dump id all custom 1 {} {}", dump_file, fields));
+    command("dump_modify id units yes");
+    command("run 0");
+    if (!verbose) ::testing::internal::GetCapturedStdout();
+
+
+    ASSERT_FILE_EXISTS(dump_file);
+    auto lines = read_lines(dump_file);
+    ASSERT_EQ(lines.size(), 43);
+    ASSERT_STREQ(lines[6].c_str(), "ITEM: BOX BOUNDS pp pp pp");
+    ASSERT_EQ(utils::split_words(lines[7]).size(), 2);
+    ASSERT_STREQ(lines[10].c_str(), fmt::format("ITEM: ATOMS {}", fields).c_str());
+    ASSERT_EQ(utils::split_words(lines[11]).size(), 8);
+    delete_file(dump_file);
+}
+
+TEST_F(DumpCustomTest, fix_run0)
+{
+    auto dump_file = "dump_custom_compute_run0.melt";
+    auto fields = "id x y z f_numdiff[1] f_numdiff[2] f_numdiff[3]";
+
+    if (!verbose) ::testing::internal::CaptureStdout();
+    command("fix numdiff all numdiff 1 0.0001");
+    command(fmt::format("dump id all custom 1 {} {}", dump_file, fields));
+    command("dump_modify id units yes");
+    command("run 0");
+    if (!verbose) ::testing::internal::GetCapturedStdout();
+
+
+    ASSERT_FILE_EXISTS(dump_file);
+    auto lines = read_lines(dump_file);
+    ASSERT_EQ(lines.size(), 43);
+    ASSERT_STREQ(lines[6].c_str(), "ITEM: BOX BOUNDS pp pp pp");
+    ASSERT_EQ(utils::split_words(lines[7]).size(), 2);
+    ASSERT_STREQ(lines[10].c_str(), fmt::format("ITEM: ATOMS {}", fields).c_str());
+    ASSERT_EQ(utils::split_words(lines[11]).size(), 7);
+    delete_file(dump_file);
+}
+
+TEST_F(DumpCustomTest, custom_run0)
+{
+    auto dump_file = "dump_custom_custom_run0.melt";
+    auto fields = "id x y z i_flag1 d_flag2";
+
+    if (!verbose) ::testing::internal::CaptureStdout();
+    command("fix prop all property/atom i_flag1 d_flag2");
+    command("compute 1 all property/atom i_flag1 d_flag2");
+    command(fmt::format("dump id all custom 1 {} {}", dump_file, fields));
+    command("dump_modify id units yes");
+    command("run 0");
+    if (!verbose) ::testing::internal::GetCapturedStdout();
+
+
+    ASSERT_FILE_EXISTS(dump_file);
+    auto lines = read_lines(dump_file);
+    ASSERT_EQ(lines.size(), 43);
+    ASSERT_STREQ(lines[6].c_str(), "ITEM: BOX BOUNDS pp pp pp");
+    ASSERT_EQ(utils::split_words(lines[7]).size(), 2);
+    ASSERT_STREQ(lines[10].c_str(), fmt::format("ITEM: ATOMS {}", fields).c_str());
     ASSERT_EQ(utils::split_words(lines[11]).size(), 6);
     delete_file(dump_file);
 }
@@ -50,12 +143,13 @@ TEST_F(DumpCustomTest, binary_run1)
     auto text_file = "dump_custom_text_run1.melt";
     auto binary_file = "dump_custom_binary_run1.melt.bin";
     auto converted_file = fmt::format("{}.txt", binary_file);
+    auto fields = "id type proc x y z ix iy iz xs ys zs xu yu zu xsu ysu zsu vx vy vz fx fy fz";
 
     if(!BINARY2TXT_BINARY) GTEST_SKIP();
 
     if (!verbose) ::testing::internal::CaptureStdout();
-    command(fmt::format("dump id0 all custom 1 {} id type x y vx fx", text_file));
-    command(fmt::format("dump id1 all custom 1 {} id type x y vx fx", binary_file));
+    command(fmt::format("dump id0 all custom 1 {} {}", text_file, fields));
+    command(fmt::format("dump id1 all custom 1 {} {}", binary_file, fields));
     command("dump_modify id0 units yes");
     command("dump_modify id1 units yes");
     command("run 1");
@@ -79,10 +173,12 @@ TEST_F(DumpCustomTest, binary_run1)
 TEST_F(DumpCustomTest, triclinic_run1)
 {
     auto dump_file = "dump_custom_tri_run1.melt";
+    auto fields = "id type proc x y z ix iy iz xs ys zs xu yu zu xsu ysu zsu vx vy vz fx fy fz";
+
     if (!verbose) ::testing::internal::CaptureStdout();
 
     command("change_box all triclinic");
-    command(fmt::format("dump id all custom 1 {} id type x y vx fx", dump_file));
+    command(fmt::format("dump id all custom 1 {} {}", dump_file, fields));
     command("dump_modify id units yes");
     command("run 1");
     if (!verbose) ::testing::internal::GetCapturedStdout();
@@ -102,12 +198,14 @@ TEST_F(DumpCustomTest, binary_triclinic_run1)
     auto text_file = "dump_custom_tri_text_run1.melt";
     auto binary_file = "dump_custom_tri_binary_run1.melt.bin";
     auto converted_file = fmt::format("{}.txt", binary_file);
+    auto fields = "id type proc x y z xs ys zs xsu ysu zsu vx vy vz fx fy fz";
 
     if(!BINARY2TXT_BINARY) GTEST_SKIP();
 
     if (!verbose) ::testing::internal::CaptureStdout();
-    command(fmt::format("dump id0 all custom 1 {} id type x y vx fx", text_file));
-    command(fmt::format("dump id1 all custom 1 {} id type x y vx fx", binary_file));
+    command("change_box all triclinic");
+    command(fmt::format("dump id0 all custom 1 {} {}", text_file, fields));
+    command(fmt::format("dump id1 all custom 1 {} {}", binary_file, fields));
     command("dump_modify id0 units yes");
     command("dump_modify id1 units yes");
     command("run 1");
@@ -128,6 +226,29 @@ TEST_F(DumpCustomTest, binary_triclinic_run1)
     delete_file(converted_file);
 }
 
+TEST_F(DumpCustomTest, with_variable_run1)
+{
+    auto dump_file = "dump_custom_with_variable_run1.melt";
+
+    if (!verbose) ::testing::internal::CaptureStdout();
+    command("compute         1 all property/atom proc");
+    command("variable        p atom (c_1%10)+1");
+    command(fmt::format("dump id all custom 1 {} id type x y z v_p", dump_file));
+    command("dump_modify id units yes");
+    command("run 1");
+    if (!verbose) ::testing::internal::GetCapturedStdout();
+
+
+    ASSERT_FILE_EXISTS(dump_file);
+    auto lines = read_lines(dump_file);
+    ASSERT_EQ(lines.size(), 84);
+    ASSERT_STREQ(lines[6].c_str(), "ITEM: BOX BOUNDS pp pp pp");
+    ASSERT_EQ(utils::split_words(lines[7]).size(), 2);
+    ASSERT_STREQ(lines[10].c_str(), "ITEM: ATOMS id type x y z v_p");
+    ASSERT_EQ(utils::split_words(lines[11]).size(), 6);
+    delete_file(dump_file);
+}
+
 
 int main(int argc, char **argv)
 {
diff --git a/unittest/testing/systems/melt.h b/unittest/testing/systems/melt.h
index 084e81cf74..9410b6ea77 100644
--- a/unittest/testing/systems/melt.h
+++ b/unittest/testing/systems/melt.h
@@ -20,6 +20,7 @@ protected:
     virtual void InitSystem() override {
         command("units           lj");
         command("atom_style      atomic");
+        command("atom_modify     map yes");
 
         command("lattice         fcc 0.8442");
         command("region          box block 0 2 0 2 0 2");