diff --git a/R/ContingencyTableTest.R b/R/ContingencyTableTest.R
index 884526ed..42b9846c 100644
--- a/R/ContingencyTableTest.R
+++ b/R/ContingencyTableTest.R
@@ -19,7 +19,7 @@ ContingencyTableTest <- R6Class(
             }
 
             private$.data <- unname(
-                do_call(cbind, lapply(private$.raw_data, as.integer))
+                do.call(cbind, lapply(private$.raw_data, as.integer))
             )
 
             if (any(private$.data < 0)) {
diff --git a/R/RCBDTest.R b/R/RCBDTest.R
index 9ac0b78b..65179ea3 100644
--- a/R/RCBDTest.R
+++ b/R/RCBDTest.R
@@ -18,7 +18,7 @@ RCBDTest <- R6Class(
                 stop("All samples must be of equal length")
             }
 
-            private$.data <- unname(do_call(cbind, private$.raw_data))
+            private$.data <- unname(do.call(cbind, private$.raw_data))
         },
 
         .calculate_score = function() {
diff --git a/R/TwoSampleAssociationTest.R b/R/TwoSampleAssociationTest.R
index a196ad5e..c18e80cd 100644
--- a/R/TwoSampleAssociationTest.R
+++ b/R/TwoSampleAssociationTest.R
@@ -20,7 +20,7 @@ TwoSampleAssociationTest <- R6Class(
                 stop("Both samples must be of equal length")
             }
 
-            private$.data <- do_call(data.frame, private$.data)
+            private$.data <- do.call(data.frame, private$.data)
         },
 
         .calculate_score = function() {},
diff --git a/R/TwoSamplePairedTest.R b/R/TwoSamplePairedTest.R
index fffe20b6..1a98f97c 100644
--- a/R/TwoSamplePairedTest.R
+++ b/R/TwoSamplePairedTest.R
@@ -20,7 +20,7 @@ TwoSamplePairedTest <- R6Class(
                 stop("Both samples must be of equal length")
             }
 
-            private$.data <- do_call(data.frame, private$.data)
+            private$.data <- do.call(data.frame, private$.data)
         },
 
         .calculate_score = function() {},
diff --git a/R/utils.R b/R/utils.R
index 3d0ec142..92f48666 100644
--- a/R/utils.R
+++ b/R/utils.R
@@ -1,14 +1,3 @@
-do_call <- function(func, default = NULL, fixed = NULL, ...) {
-    env_args <- list2env(as.list(default))
-    env_args <- list2env(list(...), envir = env_args)
-    env_args <- list2env(as.list(fixed), envir = env_args)
-
-    eval(
-        as.call(c(func, sapply(names(env_args), as.name, simplify = FALSE))),
-        envir = env_args, enclos = parent.frame()
-    )
-}
-
 # for test()
 
 get_data <- function(call, env) {
@@ -43,6 +32,19 @@ get_data <- function(call, env) {
     ), data_names)
 }
 
+# for plot()
+
+do_call <- function(func, default = NULL, fixed = NULL, ...) {
+    env_args <- list2env(as.list(default))
+    env_args <- list2env(list(...), envir = env_args)
+    env_args <- list2env(as.list(fixed), envir = env_args)
+
+    eval(
+        as.call(c(func, sapply(names(env_args), as.name, simplify = FALSE))),
+        envir = env_args, enclos = parent.frame()
+    )
+}
+
 # for .calculate_score()
 
 get_score <- function(x, method, n = length(x)) {