diff --git a/unittest/cplusplus/test_advanced_utils.cpp b/unittest/cplusplus/test_advanced_utils.cpp
index ee39f67f34..46da2d5d4b 100644
--- a/unittest/cplusplus/test_advanced_utils.cpp
+++ b/unittest/cplusplus/test_advanced_utils.cpp
@@ -125,55 +125,98 @@ TEST_F(Advanced_utils, expand_args)
 
     char **args, **earg;
     constexpr int oarg = 9;
-    args    = new char *[oarg];
-    args[0] = utils::strdup("v_step");
-    args[1] = utils::strdup("c_temp");
-    args[2] = utils::strdup("f_1[2*]");
-    args[3] = utils::strdup("c_temp[2*4]");
-    args[4] = utils::strdup("v_temp[*4]");
-    args[5] = utils::strdup("c_rdf[*]");
-    args[6] = utils::strdup("c_rdf[1][*]");
-    args[7] = utils::strdup("c_rdf[*][2]");
-    args[8] = utils::strdup("c_rdf[*][*]");
+    args               = new char *[oarg];
+    args[0]            = utils::strdup("v_step");
+    args[1]            = utils::strdup("c_temp");
+    args[2]            = utils::strdup("f_1[*]");
+    args[3]            = utils::strdup("c_temp[2*4]");
+    args[4]            = utils::strdup("v_temp[*4]");
+    args[5]            = utils::strdup("c_gofr[3*]");
+    args[6]            = utils::strdup("c_gofr[1][*]");
+    args[7]            = utils::strdup("c_gofr[*2][2]");
+    args[8]            = utils::strdup("c_gofr[*][*]");
 
     auto narg = utils::expand_args(FLERR, oarg, args, 0, earg, lmp);
-    EXPECT_EQ(narg, 12);
+    EXPECT_EQ(narg, 16);
     EXPECT_STREQ(earg[0], "v_step");
     EXPECT_STREQ(earg[1], "c_temp");
-    EXPECT_STREQ(earg[2], "f_1[2]");
-    EXPECT_STREQ(earg[3], "f_1[3]");
-    EXPECT_STREQ(earg[4], "c_temp[2]");
-    EXPECT_STREQ(earg[5], "c_temp[3]");
-    EXPECT_STREQ(earg[6], "c_temp[4]");
-    EXPECT_STREQ(earg[7], "v_temp[*4]");
-    EXPECT_STREQ(earg[8], "c_rdf[*]");
-    EXPECT_STREQ(earg[9], "c_rdf[1][*]");
-    EXPECT_STREQ(earg[10], "c_rdf[*][2]");
-    EXPECT_STREQ(earg[11], "c_rdf[*][*]");
+    EXPECT_STREQ(earg[2], "f_1[1]");
+    EXPECT_STREQ(earg[3], "f_1[2]");
+    EXPECT_STREQ(earg[4], "f_1[3]");
+    EXPECT_STREQ(earg[5], "c_temp[2]");
+    EXPECT_STREQ(earg[6], "c_temp[3]");
+    EXPECT_STREQ(earg[7], "c_temp[4]");
+    EXPECT_STREQ(earg[8], "v_temp[1]");
+    EXPECT_STREQ(earg[9], "v_temp[2]");
+    EXPECT_STREQ(earg[10], "v_temp[3]");
+    EXPECT_STREQ(earg[11], "v_temp[4]");
+    EXPECT_STREQ(earg[12], "c_gofr[3*]");
+    EXPECT_STREQ(earg[13], "c_gofr[1][*]");
+    EXPECT_STREQ(earg[14], "c_gofr[*2][2]");
+    EXPECT_STREQ(earg[15], "c_gofr[*][*]");
 
     for (int i = 0; i < narg; ++i)
         delete[] earg[i];
     lmp->memory->sfree(earg);
 
     narg = utils::expand_args(FLERR, oarg, args, 1, earg, lmp);
-    EXPECT_EQ(narg, oarg);
+    EXPECT_EQ(narg, 16);
     EXPECT_NE(args, earg);
     EXPECT_STREQ(earg[0], "v_step");
     EXPECT_STREQ(earg[1], "c_temp");
-    EXPECT_STREQ(earg[2], "f_1[2*]");
+    EXPECT_STREQ(earg[2], "f_1[*]");
     EXPECT_STREQ(earg[3], "c_temp[2*4]");
     EXPECT_STREQ(earg[4], "v_temp[*4]");
-    EXPECT_STREQ(earg[5], "c_rdf[*]");
-    EXPECT_STREQ(earg[6], "c_rdf[1][*]");
-    EXPECT_STREQ(earg[7], "c_rdf[*][2]");
-    EXPECT_STREQ(earg[8], "c_rdf[*][*]");
+    EXPECT_STREQ(earg[5], "c_gofr[3]");
+    EXPECT_STREQ(earg[6], "c_gofr[4]");
+    EXPECT_STREQ(earg[7], "c_gofr[5]");
+    EXPECT_STREQ(earg[8], "c_gofr[1][*]");
+    EXPECT_STREQ(earg[9], "c_gofr[1][2]");
+    EXPECT_STREQ(earg[10], "c_gofr[2][2]");
+    EXPECT_STREQ(earg[11], "c_gofr[1][*]");
+    EXPECT_STREQ(earg[12], "c_gofr[2][*]");
+    EXPECT_STREQ(earg[13], "c_gofr[3][*]");
+    EXPECT_STREQ(earg[14], "c_gofr[4][*]");
+    EXPECT_STREQ(earg[15], "c_gofr[5][*]");
 
-    for (int i = 0; i < oarg; ++i)
-        delete[] args[i];
-    delete[] args;
     for (int i = 0; i < narg; ++i)
         delete[] earg[i];
     lmp->memory->sfree(earg);
+
+    args[3][9] = '9';
+    TEST_FAILURE("ERROR: Numeric index 9 is out of bounds \\(1-6\\).*",
+                 utils::expand_args(FLERR, oarg, args, 0, earg, lmp););
+
+    args[3][9] = '4';
+    args[5][7] = '9';
+    TEST_FAILURE("ERROR: Numeric index 9 is out of bounds \\(1-5\\).*",
+                 utils::expand_args(FLERR, oarg, args, 1, earg, lmp););
+
+    args[5][7] = '3';
+    delete[] args[4];
+    args[4] = utils::strdup("v_temp[2*]");
+    narg    = utils::expand_args(FLERR, oarg, args, 0, earg, lmp);
+    EXPECT_EQ(narg, 13);
+    EXPECT_STREQ(earg[0], "v_step");
+    EXPECT_STREQ(earg[1], "c_temp");
+    EXPECT_STREQ(earg[2], "f_1[1]");
+    EXPECT_STREQ(earg[3], "f_1[2]");
+    EXPECT_STREQ(earg[4], "f_1[3]");
+    EXPECT_STREQ(earg[5], "c_temp[2]");
+    EXPECT_STREQ(earg[6], "c_temp[3]");
+    EXPECT_STREQ(earg[7], "c_temp[4]");
+    EXPECT_STREQ(earg[8], "v_temp[2*]");
+    EXPECT_STREQ(earg[9], "c_gofr[3*]");
+    EXPECT_STREQ(earg[10], "c_gofr[1][*]");
+    EXPECT_STREQ(earg[11], "c_gofr[*2][2]");
+    EXPECT_STREQ(earg[12], "c_gofr[*][*]");
+
+    for (int i = 0; i < narg; ++i)
+        delete[] earg[i];
+    lmp->memory->sfree(earg);
+    for (int i = 0; i < oarg; ++i)
+        delete[] args[i];
+    delete[] args;
 }
 
 } // namespace LAMMPS_NS