diff --git a/lib/string.c b/lib/string.c
index 730750c..a573aa6 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -37,7 +37,7 @@ void string_replace(string_t string, char search, char replace) {
   string[string_length] = '\0';
 }
 
-void string_remove_character(char* string, char search) {
+void string_remove_character(string_t string, char search) {
   size_t string_length = string_get_length(string);
   for (size_t index = 0; index < string_length; index++) {
     if (string[index] == search) {
diff --git a/lib/string.h b/lib/string.h
index a03a1b4..2a439f9 100644
--- a/lib/string.h
+++ b/lib/string.h
@@ -61,7 +61,7 @@ void string_replace(string_t string, char search, char replace);
  * @param search A character search value.
  * @since v4.1.0
  */
-void string_remove_character(char* string, char search);
+void string_remove_character(string_t string, char search);
 
 /**
  * @brief Removes all `character` from the start of a string.
diff --git a/lib/terminal.c b/lib/terminal.c
index 2590732..4ee3ca1 100644
--- a/lib/terminal.c
+++ b/lib/terminal.c
@@ -24,7 +24,7 @@ string_t terminal_input() {
 void terminal_print_array(void* array, size_t array_size, size_t element_size, void (*print_element)(void*)) {
   printf("[");
   for (size_t index = 0; index < array_size; index++) {
-    void* element = (char*)array + index * element_size;
+    void* element = (string_t)array + index * element_size;
     print_element(element);
     bool is_last = index == array_size - 1;
     if (!is_last) {
@@ -47,11 +47,11 @@ void terminal_print_unsigned_long(void* value) {
 }
 
 void terminal_print_char(void* value) {
-  printf("%c", *(char*)value);
+  printf("%c", *(string_t)value);
 }
 
 void terminal_print_string(void* value) {
-  printf("%s", (char*)value);
+  printf("%s", (string_t)value);
 }
 
 void terminal_print_stack(struct stack* stack, void (*print_element)(void*)) {
@@ -63,7 +63,7 @@ void terminal_print_stack(struct stack* stack, void (*print_element)(void*)) {
   struct stack_node* node_current = stack->first;
   while (node_current != NULL) {
     printf("|\t");
-    void* element = (char*)node_current->data;
+    void* element = node_current->data;
     print_element(&element);
     node_current = node_current->next;
     printf("\t|\n");
@@ -79,7 +79,7 @@ void terminal_print_queue(struct queue* queue, void (*print_element)(void*)) {
   struct queue_node* node_current = queue->first;
   while (node_current != NULL) {
     printf("|\t");
-    void* element = (char*)node_current->data;
+    void* element = node_current->data;
     print_element(&element);
     node_current = node_current->next;
     printf("\t|\n");
@@ -94,7 +94,7 @@ void terminal_print_linked_list(struct linked_list* linked_list, void (*print_el
   }
   struct linked_list_node* node_current = linked_list->head;
   while (node_current != NULL) {
-    void* element = (char*)node_current->data;
+    void* element = (string_t)node_current->data;
     node_current = node_current->next;
     print_element(&element);
     printf(" -> ");
diff --git a/set_version.c b/set_version.c
index be75e86..32d4c23 100644
--- a/set_version.c
+++ b/set_version.c
@@ -3,7 +3,7 @@
 
 #include "libcproject.h"
 
-int main(int argc, char** argv) {
+int main(int argc, string_t* argv) {
   if (argc != 2) {
     fprintf(stderr, "Usage: %s <version>\n", argv[0]);
     return EXIT_FAILURE;
diff --git a/test/convert_test.c b/test/convert_test.c
index b373fd6..85df3c8 100644
--- a/test/convert_test.c
+++ b/test/convert_test.c
@@ -10,7 +10,7 @@ void convert_test() {
 }
 
 void convert_character_to_string_test() {
-  char* result = convert_character_to_string('a');
+  string_t result = convert_character_to_string('a');
   assert(assert_string_equal(result, "a"));
   free(result);
 
@@ -77,7 +77,7 @@ void convert_string_to_number_test() {
 }
 
 void convert_number_to_string_test() {
-  char* result = convert_number_to_string(0);
+  string_t result = convert_number_to_string(0);
   assert(assert_string_equal(result, "0"));
   free(result);
 
@@ -143,7 +143,7 @@ void convert_number_to_string_test() {
 }
 
 void convert_number_from_base_to_another_test() {
-  char* result = convert_number_from_base_to_another("15", 10, 16);
+  string_t result = convert_number_from_base_to_another("15", 10, 16);
   assert(assert_string_equal(result, "F"));
   free(result);
 
diff --git a/test/string_test.c b/test/string_test.c
index fc7ba75..25800af 100644
--- a/test/string_test.c
+++ b/test/string_test.c
@@ -203,7 +203,7 @@ void string_get_is_substring_test() {
 }
 
 void string_get_formatted_number_test() {
-  char* result = string_get_formatted_number(1000, " ");
+  string_t result = string_get_formatted_number(1000, " ");
   assert(assert_string_equal(result, "1 000"));
   free(result);
 
@@ -235,7 +235,7 @@ void string_get_formatted_number_test() {
 void string_get_last_occurence_of_character_test() {
   string_t string = "abcdef";
 
-  char* result = string_get_last_occurence_of_character(string, 'a');
+  string_t result = string_get_last_occurence_of_character(string, 'a');
   assert(assert_string_equal(result, "abcdef"));
   free(result);