diff --git a/.clang-format b/.clang-format
index e0464987424a02d9daacc7730a9c49519f1cd175..8e3945de245a7bd55da09677b090e927d1002a72 100644
--- a/.clang-format
+++ b/.clang-format
@@ -68,6 +68,6 @@ SpacesInCStyleCastParentheses: false
 SpacesInContainerLiterals: false
 SpacesInParentheses: false
 SpacesInSquareBrackets: false
-Standard: c++14
+Standard: c++17
 TabWidth: 4
 UseTab: Never
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 73badb0a6dec37f5615659a4d38e22ef9b94d669..1ed0824937097cdada6ff86238f9d97dbdb922fc 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -29,7 +29,7 @@ image: gekkofs/gekkofs:build_env-0.8.0
 check format:
   stage: check format
   script:
-    - ${CI_PROJECT_DIR}/scripts/check_format.sh -s "${CI_PROJECT_DIR}/src" -i "${CI_PROJECT_DIR}/src"
+    - ${CI_PROJECT_DIR}/scripts/check_format.sh -s "${CI_PROJECT_DIR}/src" -i "${CI_PROJECT_DIR}/src" -v
 
 compile dependencies:
   stage: build deps
diff --git a/scripts/check_format.sh b/scripts/check_format.sh
index d58c045b71a85ea447dbdd28192dd8c6e8ba0cdc..c178ebc38838b648f8b9168bbdec2faa8e3910a8 100755
--- a/scripts/check_format.sh
+++ b/scripts/check_format.sh
@@ -4,6 +4,7 @@ PROJECT_SRC="$(pwd)/src"
 PROJECT_INCLUDE="$(pwd)/include"
 RUN_FORMAT=false
 CLANG_FORMAT_BIN=""
+VERBOSE=false
 
 usage_short() {
     echo "
@@ -30,6 +31,7 @@ optional arguments:
                         (default: looks for 'clang-format' or 'clang-format-10')
     -r, --run_format    run clang-formatter before formatting check
                         DISCLAIMER: FILES ARE MODIFIED IN PLACE!
+    -v, --verbose       shows the diff of all files
 "
 }
 
@@ -61,6 +63,10 @@ while [[ $# -gt 0 ]]; do
         RUN_FORMAT=true
         shift # past argument
         ;;
+    -v | --verbose)
+        VERBOSE=true
+        shift # past argument
+        ;;
     -h | --help)
         help_msg
         exit
@@ -115,6 +121,11 @@ while IFS= read -r -d '' FILE; do
         else
             echo -n "$FILE "
             echo "$UNFORMATTED_LINES"
+            if [[ "$VERBOSE" == true ]]; then
+                diff -u <(cat "$FILE") <($CLANG_FORMAT_BIN -style=file "$FILE")
+                echo "_______________________________________________________"
+            fi
+            echo
             FAIL=true
         fi
     fi