diff --git a/src/validation/context.rs b/src/validation/context.rs
index 0de49de..4815a5a 100644
--- a/src/validation/context.rs
+++ b/src/validation/context.rs
@@ -2,6 +2,7 @@ use elements::{MemoryType, TableType, GlobalType, Type};
 use elements::{BlockType, ValueType};
 use validation::Error;
 
+#[derive(Default, Debug)]
 pub struct ModuleContext {
 	pub memories: Vec<MemoryType>,
 	pub tables: Vec<TableType>,
diff --git a/src/validation/mod.rs b/src/validation/mod.rs
index 437ed9a..bfcc325 100644
--- a/src/validation/mod.rs
+++ b/src/validation/mod.rs
@@ -16,6 +16,7 @@ mod func;
 #[cfg(test)]
 mod tests;
 
+#[derive(Debug)]
 pub struct Error(String);
 
 impl fmt::Display for Error {
@@ -182,8 +183,6 @@ fn prepare_context(module: &Module) -> Result<ModuleContext, Error> {
 		.unwrap_or_default();
 
 	// Fill elements with imported values.
-
-	// TODO: Use Func::type_ref?
 	let mut func_type_indexes = Vec::new();
 	let mut tables = Vec::new();
 	let mut memories = Vec::new();
diff --git a/src/validation/module.rs b/src/validation/module.rs
index e601664..1e138a1 100644
--- a/src/validation/module.rs
+++ b/src/validation/module.rs
@@ -1,5 +1,6 @@
 use elements::{MemoryType, TableType, GlobalType, Type};
 
+#[derive(Debug)]
 pub struct ValidatedModule {
 	pub memories: Vec<MemoryType>,
 	pub tables: Vec<TableType>,
diff --git a/src/validation/tests.rs b/src/validation/tests.rs
index 6cd49e9..1ad6448 100644
--- a/src/validation/tests.rs
+++ b/src/validation/tests.rs
@@ -1,7 +1,7 @@
 use super::validate_module;
 use builder::module;
 use elements::{External, GlobalEntry, GlobalType, ImportEntry, InitExpr, MemoryType,
-               Opcode, Opcodes, TableType, ValueType};
+               Opcode, Opcodes, TableType, ValueType, BlockType};
 
 #[test]
 fn empty_is_valid() {
@@ -275,23 +275,25 @@ fn globals() {
 	assert!(validate_module(&m).is_err());
 }
 
-// TODO: pepyakin
-// #[test]
-// fn if_else_with_return_type_validation() {
-// 	let module_instance = ModuleInstance::new(Weak::default(), "test".into(), module().build()).unwrap();
-// 	let mut context = FunctionValidationContext::new(&module_instance, None, &[], 1024, 1024, FunctionSignature::Module(&FunctionType::default()));
-
-// 	Validator::validate_function(&mut context, BlockType::NoResult, &[
-// 		Opcode::I32Const(1),
-// 		Opcode::If(BlockType::NoResult),
-// 			Opcode::I32Const(1),
-// 			Opcode::If(BlockType::Value(ValueType::I32)),
-// 				Opcode::I32Const(1),
-// 			Opcode::Else,
-// 				Opcode::I32Const(2),
-// 			Opcode::End,
-// 		Opcode::Drop,
-// 		Opcode::End,
-// 		Opcode::End,
-// 	]).unwrap();
-// }
+#[test]
+fn if_else_with_return_type_validation() {
+	let m = module()
+		.function()
+			.signature().build()
+			.body().with_opcodes(Opcodes::new(vec![
+				Opcode::I32Const(1),
+				Opcode::If(BlockType::NoResult),
+					Opcode::I32Const(1),
+					Opcode::If(BlockType::Value(ValueType::I32)),
+						Opcode::I32Const(1),
+					Opcode::Else,
+						Opcode::I32Const(2),
+					Opcode::End,
+					Opcode::Drop,
+				Opcode::End,
+				Opcode::End,
+			])).build()
+			.build()
+		.build();
+	validate_module(&m).unwrap();
+}