diff --git a/capi/include/yara_x.h b/capi/include/yara_x.h
index a44fcb56b..1dbe05b37 100644
--- a/capi/include/yara_x.h
+++ b/capi/include/yara_x.h
@@ -452,9 +452,9 @@ enum YRX_RESULT yrx_compiler_define_global_float(struct YRX_COMPILER *compiler,
 // (e.g., booleans, integers, strings), prefer dedicated functions to avoid
 // the overhead of JSON deserialization.
 //
-// When defining a map, keys must be of string type and valid YARA identifiers,
-// and values can be any of the types supported by YARA, including other maps.
-// Arrays must be homogeneous (all elements must be the same type).
+// When defining a map, keys must be of string type, and values can be
+// any of the types supported by YARA, including other maps. Arrays must be
+// homogeneous (all elements must be the same type).
 enum YRX_RESULT yrx_compiler_define_global_json(struct YRX_COMPILER *compiler,
                                                 const char *ident,
                                                 const char *value);
diff --git a/ls/src/features/diagnostics.rs b/ls/src/features/diagnostics.rs
index f3214c7e8..a1ef59858 100644
--- a/ls/src/features/diagnostics.rs
+++ b/ls/src/features/diagnostics.rs
@@ -69,6 +69,14 @@ pub fn compiler_diagnostics(
 
     let mut compiler = Compiler::new();
 
+    // These features are required by the "vt" module. Some field will be
+    // recognized only if these features are enabled.
+    compiler
+        .enable_feature("file")
+        .enable_feature("url")
+        .enable_feature("ip_address")
+        .enable_feature("domain");
+
     if let Some(regex) = rule_name_validation {
         if let Ok(linter) = linters::rule_name(regex) {
             compiler.add_linter(linter);