diff --git a/plugins/libimhex/include/hex/lang/ast_node.hpp b/plugins/libimhex/include/hex/lang/ast_node.hpp
index 8a6782424..d236b6333 100644
--- a/plugins/libimhex/include/hex/lang/ast_node.hpp
+++ b/plugins/libimhex/include/hex/lang/ast_node.hpp
@@ -569,7 +569,7 @@ namespace hex::lang {
 
     class ASTNodeAttribute : public ASTNode {
     public:
-        explicit ASTNodeAttribute(std::string_view attribute, std::string_view value = { })
+        explicit ASTNodeAttribute(std::string_view attribute, std::optional<std::string_view> value = { })
             : ASTNode(), m_attribute(attribute), m_value(value) { }
 
         ~ASTNodeAttribute() override = default;
diff --git a/plugins/libimhex/source/lang/evaluator.cpp b/plugins/libimhex/source/lang/evaluator.cpp
index a86f77be5..080dfa399 100644
--- a/plugins/libimhex/source/lang/evaluator.cpp
+++ b/plugins/libimhex/source/lang/evaluator.cpp
@@ -113,7 +113,8 @@ namespace hex::lang {
         PatternData *currPattern = nullptr;
 
         // Local variable access
-        currPattern = this->findPattern(*this->m_localVariables.back(), path);
+        if (!this->m_localVariables.empty())
+            currPattern = this->findPattern(*this->m_localVariables.back(), path);
 
         // If no local variable was found try local structure members
         if (this->m_currMembers.size() > 1) {
diff --git a/plugins/libimhex/source/lang/parser.cpp b/plugins/libimhex/source/lang/parser.cpp
index f25534554..85c01a5fe 100644
--- a/plugins/libimhex/source/lang/parser.cpp
+++ b/plugins/libimhex/source/lang/parser.cpp
@@ -365,7 +365,8 @@ namespace hex::lang {
         std::vector<std::string> params;
 
         // Parse parameter list
-        while (MATCHES(sequence(IDENTIFIER))) {
+        bool hasParams = MATCHES(sequence(IDENTIFIER));
+        while (hasParams) {
             params.push_back(getValue<std::string>(-1));
 
             if (!MATCHES(sequence(SEPARATOR_COMMA))) {
@@ -375,6 +376,10 @@ namespace hex::lang {
                     throwParseError("expected closing ')' after parameter list");
             }
         }
+        if (!hasParams) {
+            if (!MATCHES(sequence(SEPARATOR_ROUNDBRACKETCLOSE)))
+                throwParseError("expected closing ')' after parameter list");
+        }
 
         if (!MATCHES(sequence(SEPARATOR_CURLYBRACKETOPEN)))
             throwParseError("expected opening '{' after function definition");