diff --git a/R/check_trans_probs.R b/R/check_trans_probs.R
index cdd9d71..0f3d860 100644
--- a/R/check_trans_probs.R
+++ b/R/check_trans_probs.R
@@ -1,7 +1,7 @@
 #' Check Transition Probability Matrix
 #'
 #' This function checks the properties of a transition probability matrix conform to
-#' standard expectations. That it is: symmetric, numeric, values are between 0
+#' standard expectations. That it is: square, numeric, values are between 0
 #' and 1 with all rows summing to 1. If a dead state is provided, it checks that the dead
 #' state -> dead state probability is 1.
 #'
@@ -40,9 +40,9 @@ check_trans_prob_mat <- function(m_P,
   # no warnings
   no_warnings <- T
 
-  # Check that the matrix is symmetric
+  # Check that the matrix is square
   if (ncol(m_P) != nrow(m_P)) {
-    message <- "Transition matrix is not symmetric."
+    message <- "Transition matrix is not square."
     no_warnings <- F
     if (stop_if_not) {
       stop(message)
@@ -200,9 +200,9 @@ check_array_names_complete <- function(a_P, stop_if_not = F){
   n_row <- dim(a_P)[1]
   n_col <- dim(a_P)[2]
 
-  # Check that the array is symmetric on dim 1 and 2
+  # Check that the array is square on dim 1 and 2
   if (n_row != n_col) {
-    message <- paste0("Transition array is not symmetric: ", n_row, " rows, and ", n_col, " columns")
+    message <- paste0("Transition array is not square: ", n_row, " rows, and ", n_col, " columns")
     no_warnings <- F
     if (stop_if_not) {
       stop(message)
@@ -266,7 +266,7 @@ check_dead_state_rows <- function(a_P, dead_state = NULL, stop_if_not = F) {
 #'
 #' This function checks the properties of a transition probability array with
 #' 2 or three dimensions conform to standard expectations. That it is that each slice is:
-#' symmetric, numeric, values are between 0 and 1 with all rows summing to 1.
+#' square, numeric, values are between 0 and 1 with all rows summing to 1.
 #' If a dead state is provided, it checks that the dead state -> dead state probability
 #' in each slice is equal to 1.
 #'
diff --git a/README.Rmd b/README.Rmd
index 18a0e05..b63b33f 100644
--- a/README.Rmd
+++ b/README.Rmd
@@ -102,7 +102,7 @@ for(x in 1:n_t){
 }
 
 # Use the function from the package.
-# This check should return no error, the array is symmetric, numeric, values 
+# This check should return no error, the array is square, numeric, values 
 # are between 0 and 1 and all rows sum to 1.
 # Note: stop_if_not = F returns warnings, stop_if_not = T returns errors.
 check_trans_prob_array(a_P = a_P, 
diff --git a/README.md b/README.md
index e5ab959..3f3ec4b 100644
--- a/README.md
+++ b/README.md
@@ -131,7 +131,7 @@ for(x in 1:n_t){
 }
 
 # Use the function from the package.
-# This check should return no error, the array is symmetric, numeric, values 
+# This check should return no error, the array is square, numeric, values 
 # are between 0 and 1 and all rows sum to 1.
 # Note: stop_if_not = F returns warnings, stop_if_not = T returns errors.
 check_trans_prob_array(a_P = a_P, 
diff --git a/man/check_trans_prob_array.Rd b/man/check_trans_prob_array.Rd
index 0f20878..4f2e25a 100644
--- a/man/check_trans_prob_array.Rd
+++ b/man/check_trans_prob_array.Rd
@@ -19,7 +19,7 @@ A message indicating whether the array passed all the checks or a warning/error
 \description{
 This function checks the properties of a transition probability array with
 2 or three dimensions conform to standard expectations. That it is that each slice is:
-symmetric, numeric, values are between 0 and 1 with all rows summing to 1.
+square, numeric, values are between 0 and 1 with all rows summing to 1.
 If a dead state is provided, it checks that the dead state -> dead state probability
 in each slice is equal to 1.
 }
diff --git a/man/check_trans_prob_mat.Rd b/man/check_trans_prob_mat.Rd
index 7dd3d32..e9453b6 100644
--- a/man/check_trans_prob_mat.Rd
+++ b/man/check_trans_prob_mat.Rd
@@ -20,7 +20,7 @@ A message indicating whether the matrix passed all the checks or a warning/error
 }
 \description{
 This function checks the properties of a transition probability matrix conform to
-standard expectations. That it is: symmetric, numeric, values are between 0
+standard expectations. That it is: square, numeric, values are between 0
 and 1 with all rows summing to 1. If a dead state is provided, it checks that the dead
 state -> dead state probability is 1.
 }
diff --git a/tests/testthat/test-check_trans_probs.R b/tests/testthat/test-check_trans_probs.R
index fbab8dc..7fc13b0 100644
--- a/tests/testthat/test-check_trans_probs.R
+++ b/tests/testthat/test-check_trans_probs.R
@@ -64,7 +64,7 @@ test_that(desc = "check_trans_prob_mat should issue warnings (or errors) for inv
 
             check_trans_prob_mat(m_P, stop_if_not = F) |>
               capture_warnings() |>
-              expect_equal(expected = "Transition matrix is not symmetric.")
+              expect_equal(expected = "Transition matrix is not square.")
 
             check_trans_prob_mat(m_P, stop_if_not = T) |>
               expect_error()