diff --git a/propertySet.go b/propertySet.go
index 4cb8115..d5c07e2 100644
--- a/propertySet.go
+++ b/propertySet.go
@@ -513,22 +513,11 @@ func invalidPropertyValue(tag PropertyName, value any) {
 
 func isConstantName(text string) (bool, string) {
 	len := len(text)
-	if len <= 1 || text[0] != '@' {
+	if len <= 1 || text[0] != '@' ||
+		strings.ContainsAny(text, ",;|\"'`+(){}[]<>/\\*&%! \t\n\r") {
 		return false, ""
 	}
 
-	if len > 2 {
-		last := len - 1
-		if (text[1] == '`' && text[last] == '`') ||
-			(text[1] == '"' && text[last] == '"') ||
-			(text[1] == '\'' && text[last] == '\'') {
-			return true, text[2:last]
-		}
-	}
-
-	if strings.ContainsAny(text, ",;|\"'`+(){}[]<>/\\*&%! \t\n\r") {
-		return false, ""
-	}
 	return true, text[1:]
 }
 
diff --git a/sessionTheme.go b/sessionTheme.go
index 21bb2e7..c0590bf 100644
--- a/sessionTheme.go
+++ b/sessionTheme.go
@@ -61,7 +61,7 @@ func (session *sessionData) resolveConstants(value string) (string, bool) {
 }
 
 func (session *sessionData) resolveConstantsNext(value string, prevTags []string) (string, bool) {
-	if !strings.Contains(value, "@") {
+	if !strings.ContainsRune(value, '@') {
 		return value, true
 	}