diff --git a/bin/commit-msg b/bin/commit-msg
index e10d38b..86e7dc7 100755
--- a/bin/commit-msg
+++ b/bin/commit-msg
@@ -22,6 +22,7 @@ done
 ALLOWED_TYPES="feat fix chore docs style refactor test ci perf build"
 MAX_SUBJECT_LENGTH=72
 AUTO_CORRECT=true
+REQUIRE_SCOPE=false
 
 # Parse config if available (simple JSON parsing with grep/sed)
 if [[ -n "$CONFIG_FILE" ]]; then
@@ -29,6 +30,7 @@ if [[ -n "$CONFIG_FILE" ]]; then
     ALLOWED_TYPES=$(jq -r '.types // empty | join(" ")' "$CONFIG_FILE" 2>/dev/null || echo "$ALLOWED_TYPES")
     MAX_SUBJECT_LENGTH=$(jq -r '.maxSubjectLength // empty' "$CONFIG_FILE" 2>/dev/null || echo "$MAX_SUBJECT_LENGTH")
     AUTO_CORRECT=$(jq -r '.autoCorrect // empty' "$CONFIG_FILE" 2>/dev/null || echo "$AUTO_CORRECT")
+    REQUIRE_SCOPE=$(jq -r '.requireScope // empty' "$CONFIG_FILE" 2>/dev/null || echo "$REQUIRE_SCOPE")
   fi
 fi
 
@@ -47,8 +49,8 @@ SUBJECT=$(echo "$SUBJECT" | sed 's/^[[:space:]]*//;s/[[:space:]]*$//')
 # Collapse multiple spaces
 SUBJECT=$(echo "$SUBJECT" | sed 's/[[:space:]]\+/ /g')
 
-# Pattern: type(scope): description  OR  type: description
-CONVENTIONAL_RE='^([a-zA-Z]+)(\([a-zA-Z0-9_. /-]*\))?[[:space:]]*:[[:space:]]*(.*)'
+# Pattern: type(scope)!: description  OR  type!: description  OR  type(scope): description  OR  type: description
+CONVENTIONAL_RE='^([a-zA-Z]+)(\([a-zA-Z0-9_. /-]*\))?(!)?\s*:\s*(.*)'
 
 normalize_type() {
   echo "$1" | tr '[:upper:]' '[:lower:]'
@@ -67,7 +69,8 @@ validate_type() {
 if [[ "$SUBJECT" =~ $CONVENTIONAL_RE ]]; then
   RAW_TYPE="${BASH_REMATCH[1]}"
   SCOPE="${BASH_REMATCH[2]}"
-  DESC="${BASH_REMATCH[3]}"
+  BREAKING="${BASH_REMATCH[3]}"
+  DESC="${BASH_REMATCH[4]}"
 
   TYPE=$(normalize_type "$RAW_TYPE")
   DESC=$(echo "$DESC" | sed 's/^[[:space:]]*//;s/[[:space:]]*$//')
@@ -82,12 +85,18 @@ if [[ "$SUBJECT" =~ $CONVENTIONAL_RE ]]; then
     exit 1
   fi
 
+  # Enforce requireScope
+  if [[ "$REQUIRE_SCOPE" == "true" && -z "$SCOPE" ]]; then
+    echo "ERROR: Scope is required. Use format: type(scope): description" >&2
+    exit 1
+  fi
+
   # Lowercase first char of description
   if [[ "$AUTO_CORRECT" == "true" ]]; then
     DESC="$(echo "${DESC:0:1}" | tr '[:upper:]' '[:lower:]')${DESC:1}"
   fi
 
-  NORMALIZED="${TYPE}${SCOPE}: ${DESC}"
+  NORMALIZED="${TYPE}${SCOPE}${BREAKING}: ${DESC}"
 else
   if [[ "$AUTO_CORRECT" != "true" ]]; then
     echo "ERROR: Commit message does not follow conventional commits format." >&2
diff --git a/tests/test_commit_msg.sh b/tests/test_commit_msg.sh
index c698cad..a60fe04 100755
--- a/tests/test_commit_msg.sh
+++ b/tests/test_commit_msg.sh
@@ -127,6 +127,62 @@ run_test "unknown type rejected" \
   "" \
   true
 
+# Breaking change with ! (no scope)
+run_test "breaking change without scope" \
+  "feat!: drop legacy API" \
+  "feat!: drop legacy API"
+
+# Breaking change with scope and !
+run_test "breaking change with scope" \
+  "fix(api)!: remove deprecated endpoint" \
+  "fix(api)!: remove deprecated endpoint"
+
+# Breaking change with uppercase type normalized
+run_test "breaking change uppercase type" \
+  "FEAT!: drop legacy API" \
+  "feat!: drop legacy API"
+
+# Breaking change with scope and uppercase
+run_test "breaking change scope uppercase" \
+  "FIX(core)!: rewrite engine" \
+  "fix(core)!: rewrite engine"
+
+# requireScope tests: create a temporary config with requireScope=true
+SCOPE_CONFIG="$TEST_REPO/commit-normalize.config.json"
+cat > "$SCOPE_CONFIG" <<'CFGEOF'
+{
+  "types": ["feat", "fix", "chore", "docs", "style", "refactor", "test", "ci", "perf", "build"],
+  "maxSubjectLength": 72,
+  "requireScope": true,
+  "autoCorrect": true
+}
+CFGEOF
+
+# With requireScope=true, commit without scope should fail
+run_test "requireScope rejects missing scope" \
+  "feat: add feature" \
+  "" \
+  true
+
+# With requireScope=true, commit with scope should pass
+run_test "requireScope accepts scope" \
+  "feat(ui): add button" \
+  "feat(ui): add button"
+
+# With requireScope=true, breaking change with scope should pass
+run_test "requireScope accepts breaking with scope" \
+  "feat(api)!: drop v1" \
+  "feat(api)!: drop v1"
+
+# With requireScope=true, breaking change without scope should fail
+run_test "requireScope rejects breaking without scope" \
+  "feat!: drop v1" \
+  "" \
+  true
+
+# Restore original config
+cp "$SCRIPT_DIR/../commit-normalize.config.json" "$TEST_REPO/"
+
 # All valid types
 for t in feat fix chore docs style refactor test ci perf build; do
   run_test "valid type: $t" \