diff --git a/CMakeLists.txt b/CMakeLists.txt
index ef62b3a..55a9b27 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,7 +1,16 @@
 cmake_minimum_required(VERSION 3.16)
 project(FortranProject LANGUAGES Fortran)
 
-add_compile_options(-Wall -Wextra -Wpedantic)
+add_compile_options(
+    -Wall
+    -Wextra
+    -Wpedantic
+    -Waliasing
+    -Wconversion-extra
+    -Wimplicit-interface
+    -Wimplicit-procedure
+    -Wsurprising
+    -Werror)
 
 function(add_fortran_sources DIR SOURCES)
     file(GLOB_RECURSE NEW_SOURCES "${DIR}/*.f90")
diff --git a/modules/sorts/merge_sort.f90 b/modules/sorts/merge_sort.f90
index 28a1861..95971ec 100644
--- a/modules/sorts/merge_sort.f90
+++ b/modules/sorts/merge_sort.f90
@@ -23,7 +23,7 @@ recursive subroutine merge_sort(array, n)
         implicit none
         integer, dimension(:), intent(inout) :: array   ! Input/output array to be sorted
         integer, intent(in) :: n                        ! Size of the array
-        integer :: middle, i
+        integer :: middle
         integer, dimension(:), allocatable :: left_half, right_half, sorted_array
 
         ! Base case: return if the array has 1 or fewer elements
diff --git a/tests/sorts/tests_gnome_sort.f90 b/tests/sorts/tests_gnome_sort.f90
index ef8d6f5..04ad524 100644
--- a/tests/sorts/tests_gnome_sort.f90
+++ b/tests/sorts/tests_gnome_sort.f90
@@ -6,7 +6,6 @@ program tests_gnome_sort
 
     use gnome_sort_module
     implicit none
-    integer :: i
     integer, dimension(:), allocatable :: array
 
     ! Test 1: Repeated elements
diff --git a/tests/sorts/tests_heap_sort.f90 b/tests/sorts/tests_heap_sort.f90
index 8b47fb3..0b28b2a 100644
--- a/tests/sorts/tests_heap_sort.f90
+++ b/tests/sorts/tests_heap_sort.f90
@@ -6,7 +6,6 @@ program tests_heap_sort
 
     use heap_sort_module
     implicit none
-    integer :: i
     integer, dimension(:), allocatable :: array
 
     ! Test 1: Repeated elements
diff --git a/tests/sorts/tests_merge_sort.f90 b/tests/sorts/tests_merge_sort.f90
index 0f44f3d..a55ef6c 100644
--- a/tests/sorts/tests_merge_sort.f90
+++ b/tests/sorts/tests_merge_sort.f90
@@ -6,7 +6,6 @@ program tests_merge_sort
 
     use merge_sort_module
     implicit none
-    integer :: i
     integer, dimension(:), allocatable :: array
 
     ! Test 1: Repeated elements
diff --git a/tests/sorts/tests_quick_sort.f90 b/tests/sorts/tests_quick_sort.f90
index 0bbfd9d..547970a 100644
--- a/tests/sorts/tests_quick_sort.f90
+++ b/tests/sorts/tests_quick_sort.f90
@@ -6,7 +6,6 @@ program tests_quick_sort
 
     use quick_sort_module
     implicit none
-    integer :: i
     integer, dimension(:), allocatable :: array
 
     ! Test 1: Repeated elements
diff --git a/tests/sorts/tests_radix_sort.f90 b/tests/sorts/tests_radix_sort.f90
index 9ccc2e0..22c04a2 100644
--- a/tests/sorts/tests_radix_sort.f90
+++ b/tests/sorts/tests_radix_sort.f90
@@ -6,7 +6,6 @@
 program tests_radix_sort
     use radix_sort_module
     implicit none
-    integer :: i
     integer, dimension(:), allocatable :: array
     integer, parameter :: base10 = 10, base2 = 2, base16 = 16