diff --git a/hook/hook.go b/hook/hook.go
index 2d2c70a..98fb975 100644
--- a/hook/hook.go
+++ b/hook/hook.go
@@ -162,7 +162,6 @@ func CheckScalrSignature(headers map[string]interface{}, body []byte, signingKey
 	}
 	// Example format: Fri 08 Sep 2017 11:24:32 UTC
 	date, err := time.Parse("Mon 02 Jan 2006 15:04:05 MST", dateHeader)
-	//date, err := time.Parse(time.RFC1123, dateHeader)
 	if err != nil {
 		return false, err
 	}
@@ -185,6 +184,7 @@ func CheckIPWhitelist(remoteAddr string, ipRange string) (bool, error) {
 
 	if i := strings.LastIndex(ip, ":"); i != -1 {
 		ip = ip[:i]
+		ip = strings.Trim(ip, " []")
 	}
 
 	parsedIP := net.ParseIP(ip)
@@ -222,7 +222,6 @@ func ReplaceParameter(s string, params interface{}, value interface{}) bool {
 
 	if paramsValue := reflect.ValueOf(params); paramsValue.Kind() == reflect.Slice {
 		if paramsValueSliceLength := paramsValue.Len(); paramsValueSliceLength > 0 {
-
 			if p := strings.SplitN(s, ".", 2); len(p) > 1 {
 				index, err := strconv.ParseUint(p[0], 10, 64)
 
@@ -257,8 +256,12 @@ func GetParameter(s string, params interface{}) (interface{}, bool) {
 		return nil, false
 	}
 
-	if paramsValue := reflect.ValueOf(params); paramsValue.Kind() == reflect.Slice {
-		if paramsValueSliceLength := paramsValue.Len(); paramsValueSliceLength > 0 {
+	paramsValue := reflect.ValueOf(params)
+
+	switch paramsValue.Kind() {
+	case reflect.Slice:
+		paramsValueSliceLength := paramsValue.Len()
+		if paramsValueSliceLength > 0 {
 
 			if p := strings.SplitN(s, ".", 2); len(p) > 1 {
 				index, err := strconv.ParseUint(p[0], 10, 64)
@@ -280,18 +283,20 @@ func GetParameter(s string, params interface{}) (interface{}, bool) {
 		}
 
 		return nil, false
-	}
 
-	if p := strings.SplitN(s, ".", 2); len(p) > 1 {
-		if paramsValue := reflect.ValueOf(params); paramsValue.Kind() == reflect.Map {
-			if pValue, ok := params.(map[string]interface{})[p[0]]; ok {
+	case reflect.Map:
+		// Check for raw key
+		if v, ok := params.(map[string]interface{})[s]; ok {
+			return v, true
+		}
+
+		// Checked for dotted references
+		p := strings.SplitN(s, ".", 2)
+		if pValue, ok := params.(map[string]interface{})[p[0]]; ok {
+			if len(p) > 1 {
 				return GetParameter(p[1], pValue)
 			}
-		} else {
-			return nil, false
-		}
-	} else {
-		if pValue, ok := params.(map[string]interface{})[p[0]]; ok {
+
 			return pValue, true
 		}
 	}
@@ -334,7 +339,6 @@ func (ha *Argument) Get(headers, query, payload *map[string]interface{}) (string
 		return ha.Name, true
 	case SourceEntirePayload:
 		r, err := json.Marshal(payload)
-
 		if err != nil {
 			return "", false
 		}
@@ -342,7 +346,6 @@ func (ha *Argument) Get(headers, query, payload *map[string]interface{}) (string
 		return string(r), true
 	case SourceEntireHeaders:
 		r, err := json.Marshal(headers)
-
 		if err != nil {
 			return "", false
 		}
@@ -350,7 +353,6 @@ func (ha *Argument) Get(headers, query, payload *map[string]interface{}) (string
 		return string(r), true
 	case SourceEntireQuery:
 		r, err := json.Marshal(query)
-
 		if err != nil {
 			return "", false
 		}
@@ -440,7 +442,7 @@ type Hook struct {
 // ParseJSONParameters decodes specified arguments to JSON objects and replaces the
 // string with the newly created object
 func (h *Hook) ParseJSONParameters(headers, query, payload *map[string]interface{}) []error {
-	var errors = make([]error, 0)
+	errors := make([]error, 0)
 
 	for i := range h.JSONStringParameters {
 		if arg, ok := h.JSONStringParameters[i].Get(headers, query, payload); ok {
@@ -450,7 +452,6 @@ func (h *Hook) ParseJSONParameters(headers, query, payload *map[string]interface
 			decoder.UseNumber()
 
 			err := decoder.Decode(&newArg)
-
 			if err != nil {
 				errors = append(errors, &ParseError{err})
 				continue
@@ -493,8 +494,8 @@ func (h *Hook) ParseJSONParameters(headers, query, payload *map[string]interface
 // ExtractCommandArguments creates a list of arguments, based on the
 // PassArgumentsToCommand property that is ready to be used with exec.Command()
 func (h *Hook) ExtractCommandArguments(headers, query, payload *map[string]interface{}) ([]string, []error) {
-	var args = make([]string, 0)
-	var errors = make([]error, 0)
+	args := make([]string, 0)
+	errors := make([]error, 0)
 
 	args = append(args, h.ExecuteCommand)
 
@@ -518,8 +519,8 @@ func (h *Hook) ExtractCommandArguments(headers, query, payload *map[string]inter
 // format, based on the PassEnvironmentToCommand property that is ready to be used
 // with exec.Command().
 func (h *Hook) ExtractCommandArgumentsForEnv(headers, query, payload *map[string]interface{}) ([]string, []error) {
-	var args = make([]string, 0)
-	var errors = make([]error, 0)
+	args := make([]string, 0)
+	errors := make([]error, 0)
 	for i := range h.PassEnvironmentToCommand {
 		if arg, ok := h.PassEnvironmentToCommand[i].Get(headers, query, payload); ok {
 			if h.PassEnvironmentToCommand[i].EnvName != "" {
@@ -552,8 +553,8 @@ type FileParameter struct {
 // format, based on the PassFileToCommand property that is ready to be used
 // with exec.Command().
 func (h *Hook) ExtractCommandArgumentsForFile(headers, query, payload *map[string]interface{}) ([]FileParameter, []error) {
-	var args = make([]FileParameter, 0)
-	var errors = make([]error, 0)
+	args := make([]FileParameter, 0)
+	errors := make([]error, 0)
 	for i := range h.PassFileToCommand {
 		if arg, ok := h.PassFileToCommand[i].Get(headers, query, payload); ok {
 
diff --git a/hook/hook_test.go b/hook/hook_test.go
index e6bfce2..e8a98bb 100644
--- a/hook/hook_test.go
+++ b/hook/hook_test.go
@@ -7,6 +7,38 @@ import (
 	"testing"
 )
 
+func TestGetParameter(t *testing.T) {
+	for _, test := range []struct {
+		key    string
+		val    interface{}
+		expect interface{}
+		ok     bool
+	}{
+		// True
+		{"a", map[string]interface{}{"a": "1"}, "1", true},
+		{"a.b", map[string]interface{}{"a.b": "1"}, "1", true},
+		{"a.c", map[string]interface{}{"a": map[string]interface{}{"c": 2}}, 2, true},
+		{"a.1", map[string]interface{}{"a": map[string]interface{}{"1": 3}}, 3, true},
+		{"a.1", map[string]interface{}{"a": []interface{}{"a", "b"}}, "b", true},
+		{"0", []interface{}{"a", "b"}, "a", true},
+
+		// False
+		{"z", map[string]interface{}{"a": "1"}, nil, false},
+		{"a.z", map[string]interface{}{"a": map[string]interface{}{"b": 2}}, nil, false},
+		{"z.b", map[string]interface{}{"a": map[string]interface{}{"z": 2}}, nil, false},
+		{"a.2", map[string]interface{}{"a": []interface{}{"a", "b"}}, nil, false},
+	} {
+		res, ok := GetParameter(test.key, test.val)
+		if ok != test.ok {
+			t.Errorf("unexpected result given {%q, %q}: %t\n", test.key, test.val, ok)
+		}
+
+		if !reflect.DeepEqual(res, test.expect) {
+			t.Errorf("failed given {%q, %q}:\nexpected {%#v}\ngot {%#v}\n", test.key, test.val, test.expect, res)
+		}
+	}
+}
+
 var checkPayloadSignatureTests = []struct {
 	payload   []byte
 	secret    string