diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index be726d163..a4fa16a8c 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -20,7 +20,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [macos-latest, windows-latest, ubuntu-latest]
+        os: [macos-latest, windows-latest, ubuntu-22.04]
     steps:
       - name: Check out Luos repository
         uses: actions/checkout@v3
@@ -44,26 +44,26 @@ jobs:
           # Run Unit tests
           platformio test -vvv
 
-      - if: matrix.os == 'ubuntu-latest'
+      - if: matrix.os == 'ubuntu-22.04'
         run: |
           sudo apt-get install -y lcov
           lcov -d .pio/build/native/ -c -o lcov.info
-          lcov --remove lcov.info '*/usr/*' '*/Platforms/*' '*/bootloader/*' '*/.pio/*' '*/HAL/*' '*/test/*' '*/network/*' -o lcov.info
+          lcov --remove lcov.info '*/usr/*' '*/Platforms/*' '*/bootloader/*' '*/.pio/*' '*/HAL/*' '*/test/*' '*/network/*' -o lcov.info --ignore-errors empty
 
-      - if: matrix.os == 'ubuntu-latest'
+      - if: matrix.os == 'ubuntu-22.04'
         name: Coveralls
         uses: coverallsapp/github-action@v2
 
   unit-tests:
     name: Unit tests
     needs: tests-run
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - run: echo "Tests succeed!"
 
   code-format:
     name: Code format
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - name: Check out Luos repository
         uses: actions/checkout@v3
@@ -89,8 +89,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        project_folders:
-          [
+        project_folders: [
             examples/projects/l0,
             examples/projects/Arduino,
             examples/projects/NUCLEO-L432KC,
@@ -106,7 +105,7 @@ jobs:
             # examples/projects/ESP32,
             examples/projects/native,
           ]
-        os: [macos-latest, windows-latest, ubuntu-latest]
+        os: [macos-latest, windows-latest, ubuntu-22.04]
 
     steps:
       - name: Check out Luos repository
@@ -152,6 +151,6 @@ jobs:
   build-success:
     name: Build success
     needs: examples-build
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - run: echo "Build succeed!"
diff --git a/engine/core/src/routing_table.c b/engine/core/src/routing_table.c
index 5af94fb67..7683ff90f 100644
--- a/engine/core/src/routing_table.c
+++ b/engine/core/src/routing_table.c
@@ -185,28 +185,18 @@ static void RoutingTB_AddNumToAlias(char *alias, uint8_t num)
     uint8_t intsize = 1;
     if (num > 9)
     {
-        // The string size of num is 2
+        // The string size of num have a size of 2
         intsize = 2;
     }
-    if (num > 99) // only 2 digit are alowed when add alias number
-    {
-        // This is probably a mistake, put an error into the alias
-        memset(alias, 0, MAX_ALIAS_SIZE - 1);
-        memcpy(alias, "error", strlen("error"));
-        return;
-    }
+    LUOS_ASSERT(num < 100); // only 2 digit are alowed when add alias number
     // Change size to fit into 15 characters
     if (strlen(alias) > (MAX_ALIAS_SIZE - 1 - intsize))
     {
         alias[(MAX_ALIAS_SIZE - 1 - intsize)] = '\0';
     }
-    else
-    {
-        alias[strlen(alias)] = '\0';
-    }
     // Add a number at the end of the alias
-    char *alias_copy = alias;
-    sprintf(alias, "%s%d", alias_copy, num);
+    char *end_pointer = &alias[strlen(alias)];
+    sprintf(end_pointer, "%d", num);
 }
 
 /******************************************************************************
diff --git a/test/tests_core/test_routing_table/main.c b/test/tests_core/test_routing_table/main.c
index d6c1b34de..031cdfe5b 100644
--- a/test/tests_core/test_routing_table/main.c
+++ b/test/tests_core/test_routing_table/main.c
@@ -197,6 +197,20 @@ void unittest_RoutingTB_AddNumToAlias(void)
         }
         TEST_ASSERT_TRUE(IS_ASSERT());
         END_TRY;
+        TRY
+        {
+            char alias[MAX_ALIAS_SIZE] = "Dummy_App";
+            RoutingTB_AddNumToAlias(alias, 100);
+        }
+        TEST_ASSERT_TRUE(IS_ASSERT());
+        END_TRY;
+        TRY
+        {
+            char alias[MAX_ALIAS_SIZE] = "Dummy_App";
+            RoutingTB_AddNumToAlias(alias, 101);
+        }
+        TEST_ASSERT_TRUE(IS_ASSERT());
+        END_TRY;
     }
 
     NEW_TEST_CASE("check RoutingTB_AddNumToAlias return value");