diff --git a/crates/analyzer/src/handlers.rs b/crates/analyzer/src/handlers.rs
index 03e0a2a7..e571622d 100644
--- a/crates/analyzer/src/handlers.rs
+++ b/crates/analyzer/src/handlers.rs
@@ -45,7 +45,6 @@ use self::{check_assignment::CheckAssignment, create_type_dag::CreateTypeDag};
 
 pub struct Pass1Handlers<'a> {
     check_attribute: CheckAttribute<'a>,
-    check_direction: CheckDirection<'a>,
     check_embed_include: CheckEmbedInclude<'a>,
     check_identifier: CheckIdentifier<'a>,
     check_number: CheckNumber<'a>,
@@ -58,7 +57,6 @@ impl<'a> Pass1Handlers<'a> {
     pub fn new(text: &'a str, build_opt: &'a Build, lint_opt: &'a Lint) -> Self {
         Self {
             check_attribute: CheckAttribute::new(text),
-            check_direction: CheckDirection::new(text),
             check_embed_include: CheckEmbedInclude::new(text),
             check_identifier: CheckIdentifier::new(text, lint_opt),
             check_number: CheckNumber::new(text),
@@ -71,7 +69,6 @@ impl<'a> Pass1Handlers<'a> {
     pub fn get_handlers(&mut self) -> Vec<&mut dyn Handler> {
         vec![
             &mut self.check_attribute as &mut dyn Handler,
-            &mut self.check_direction as &mut dyn Handler,
             &mut self.check_embed_include as &mut dyn Handler,
             &mut self.check_identifier as &mut dyn Handler,
             &mut self.check_number as &mut dyn Handler,
@@ -84,7 +81,6 @@ impl<'a> Pass1Handlers<'a> {
     pub fn get_errors(&mut self) -> Vec<AnalyzerError> {
         let mut ret = Vec::new();
         ret.append(&mut self.check_attribute.errors);
-        ret.append(&mut self.check_direction.errors);
         ret.append(&mut self.check_embed_include.errors);
         ret.append(&mut self.check_identifier.errors);
         ret.append(&mut self.check_number.errors);
@@ -97,6 +93,7 @@ impl<'a> Pass1Handlers<'a> {
 
 pub struct Pass2Handlers<'a> {
     check_enum: CheckEnum<'a>,
+    check_direction: CheckDirection<'a>,
     check_modport: CheckModport<'a>,
     check_function: CheckFunction<'a>,
     check_type: CheckType<'a>,
@@ -114,6 +111,7 @@ impl<'a> Pass2Handlers<'a> {
     pub fn new(text: &'a str, _build_opt: &'a Build, _lint_opt: &'a Lint) -> Self {
         Self {
             check_enum: CheckEnum::new(text),
+            check_direction: CheckDirection::new(text),
             check_modport: CheckModport::new(text),
             check_function: CheckFunction::new(text),
             check_type: CheckType::new(text),
@@ -131,6 +129,7 @@ impl<'a> Pass2Handlers<'a> {
     pub fn get_handlers(&mut self) -> Vec<&mut dyn Handler> {
         vec![
             &mut self.check_enum as &mut dyn Handler,
+            &mut self.check_direction as &mut dyn Handler,
             &mut self.check_modport as &mut dyn Handler,
             &mut self.check_function as &mut dyn Handler,
             &mut self.check_type as &mut dyn Handler,
@@ -148,6 +147,7 @@ impl<'a> Pass2Handlers<'a> {
     pub fn get_errors(&mut self) -> Vec<AnalyzerError> {
         let mut ret = Vec::new();
         ret.append(&mut self.check_enum.errors);
+        ret.append(&mut self.check_direction.errors);
         ret.append(&mut self.check_modport.errors);
         ret.append(&mut self.check_function.errors);
         ret.append(&mut self.check_type.errors);
diff --git a/crates/analyzer/src/handlers/check_direction.rs b/crates/analyzer/src/handlers/check_direction.rs
index 79a20ce4..a9255bbe 100644
--- a/crates/analyzer/src/handlers/check_direction.rs
+++ b/crates/analyzer/src/handlers/check_direction.rs
@@ -1,4 +1,6 @@
 use crate::analyzer_error::AnalyzerError;
+use crate::symbol::SymbolKind;
+use crate::symbol_table;
 use veryl_parser::veryl_grammar_trait::*;
 use veryl_parser::veryl_walker::{Handler, HandlerPoint};
 use veryl_parser::ParolError;
@@ -11,6 +13,7 @@ pub struct CheckDirection<'a> {
     in_function: bool,
     in_module: bool,
     in_modport: bool,
+    is_interface_port: bool,
 }
 
 impl<'a> CheckDirection<'a> {
@@ -28,6 +31,17 @@ impl<'a> Handler for CheckDirection<'a> {
     }
 }
 
+fn is_interface_type(arg: &ArrayType) -> bool {
+    if let ScalarTypeGroup::VariableTypeScalarTypeOpt(x) = &*arg.scalar_type.scalar_type_group {
+        if let VariableType::ScopedIdentifier(x) = x.variable_type.as_ref() {
+            let symbol = symbol_table::resolve(x.scoped_identifier.as_ref()).unwrap();
+            return matches!(symbol.found.kind, SymbolKind::Interface(_));
+        }
+    }
+
+    false
+}
+
 impl<'a> VerylGrammarTrait for CheckDirection<'a> {
     fn port_declaration_item(&mut self, arg: &PortDeclarationItem) -> Result<(), ParolError> {
         if let HandlerPoint::Before = self.point {
@@ -35,8 +49,10 @@ impl<'a> VerylGrammarTrait for CheckDirection<'a> {
                 arg.port_declaration_item_group.as_ref()
             {
                 let x = x.port_type_concrete.as_ref();
+                let r#type = &x.array_type;
+
+                self.is_interface_port = is_interface_type(r#type);
                 if let Direction::Inout(_) = x.direction.as_ref() {
-                    let r#type = &x.array_type;
                     let is_tri = r#type
                         .scalar_type
                         .scalar_type_list
@@ -58,8 +74,35 @@ impl<'a> VerylGrammarTrait for CheckDirection<'a> {
     fn direction(&mut self, arg: &Direction) -> Result<(), ParolError> {
         if let HandlerPoint::Before = self.point {
             match arg {
+                Direction::Input(x) => {
+                    if self.is_interface_port {
+                        self.errors.push(AnalyzerError::invalid_direction(
+                            "input",
+                            self.text,
+                            &x.input.input_token.token.into(),
+                        ));
+                    }
+                }
+                Direction::Output(x) => {
+                    if self.is_interface_port {
+                        self.errors.push(AnalyzerError::invalid_direction(
+                            "output",
+                            self.text,
+                            &x.output.output_token.token.into(),
+                        ));
+                    }
+                }
+                Direction::Inout(x) => {
+                    if self.is_interface_port {
+                        self.errors.push(AnalyzerError::invalid_direction(
+                            "inout",
+                            self.text,
+                            &x.inout.inout_token.token.into(),
+                        ));
+                    }
+                }
                 Direction::Ref(x) => {
-                    if !self.in_function {
+                    if !self.in_function || self.is_interface_port {
                         self.errors.push(AnalyzerError::invalid_direction(
                             "ref",
                             self.text,
@@ -77,7 +120,7 @@ impl<'a> VerylGrammarTrait for CheckDirection<'a> {
                     }
                 }
                 Direction::Import(x) => {
-                    if !self.in_modport {
+                    if !self.in_modport || self.is_interface_port {
                         self.errors.push(AnalyzerError::invalid_direction(
                             "import",
                             self.text,
@@ -85,7 +128,6 @@ impl<'a> VerylGrammarTrait for CheckDirection<'a> {
                         ));
                     }
                 }
-                _ => (),
             }
         }
         Ok(())
diff --git a/crates/analyzer/src/tests.rs b/crates/analyzer/src/tests.rs
index 02b8bb02..873c6348 100644
--- a/crates/analyzer/src/tests.rs
+++ b/crates/analyzer/src/tests.rs
@@ -595,6 +595,22 @@ fn invalid_direction() {
 
     let errors = analyze(code);
     assert!(matches!(errors[0], AnalyzerError::InvalidDirection { .. }));
+
+    let code = r#"
+    interface InterfaceG {
+        var value: logic;
+        modport mp {
+            value: input,
+        }
+    }
+
+    module ModuleG (
+        port_a: input InterfaceG
+    ){}
+    "#;
+
+    let errors = analyze(code);
+    assert!(matches!(errors[0], AnalyzerError::InvalidDirection { .. }));
 }
 
 #[test]