diff --git a/helpers/helpers.go b/helpers/helpers.go
index c5bbed7..9e5d88c 100644
--- a/helpers/helpers.go
+++ b/helpers/helpers.go
@@ -45,8 +45,8 @@ func ExtractParameter(s string, params interface{}) (string, bool) {
 	if paramsValue := reflect.ValueOf(params); paramsValue.Kind() == reflect.Slice {
 		if paramsValueSliceLength := paramsValue.Len(); paramsValueSliceLength > 0 {
 
-			if p := strings.SplitN(s, ".", 3); len(p) > 3 {
-				index, err := strconv.ParseInt(p[1], 10, 64)
+			if p := strings.SplitN(s, ".", 2); len(p) > 1 {
+				index, err := strconv.ParseInt(p[0], 10, 64)
 
 				if err != nil {
 					return "", false
@@ -54,7 +54,7 @@ func ExtractParameter(s string, params interface{}) (string, bool) {
 					return "", false
 				}
 
-				return ExtractParameter(p[2], params.([]map[string]interface{})[index])
+				return ExtractParameter(p[1], params.([]interface{})[index])
 			}
 		}
 
diff --git a/helpers/helpers_test.go b/helpers/helpers_test.go
new file mode 100644
index 0000000..61a54bb
--- /dev/null
+++ b/helpers/helpers_test.go
@@ -0,0 +1,29 @@
+package helpers
+
+import "testing"
+
+var extractParameterTests = []struct {
+	s      string
+	params map[string]interface{}
+	value  string
+	ok     bool
+}{
+	{"a", map[string]interface{}{"a": "z"}, "z", true},
+	{"a.b", map[string]interface{}{"a": map[string]interface{}{"b": "z"}}, "z", true},
+	{"a.b.c", map[string]interface{}{"a": map[string]interface{}{"b": map[string]interface{}{"c": "z"}}}, "z", true},
+	{"a.1.b", map[string]interface{}{"a": []interface{}{map[string]interface{}{"b": "y"}, map[string]interface{}{"b": "z"}}}, "z", true},
+	{"a.1.b.c", map[string]interface{}{"a": []interface{}{map[string]interface{}{"b": map[string]interface{}{"c": "y"}}, map[string]interface{}{"b": map[string]interface{}{"c": "z"}}}}, "z", true},
+	// failures
+	{"a.X", map[string]interface{}{"a": map[string]interface{}{"b": "z"}}, "", false},
+	{"a.500.b", map[string]interface{}{"a": map[string]interface{}{"b": "z"}}, "", false},
+	{"a.501.b", map[string]interface{}{"a": []interface{}{map[string]interface{}{"b": "y"}, map[string]interface{}{"b": "z"}}}, "", false},
+}
+
+func TestExtractParameter(t *testing.T) {
+	for _, tt := range extractParameterTests {
+		s, ok := ExtractParameter(tt.s, tt.params)
+		if ok != tt.ok || s != tt.value {
+			t.Errorf("failed to extract parameter %q:\nexpected {value:%#v, ok:%#v},\ngot {value:%#v, ok:%#v}", tt.s, tt.value, tt.ok, s, ok)
+		}
+	}
+}