diff --git a/TODO b/TODO
index 3c102fc..7f0f484 100644
--- a/TODO
+++ b/TODO
@@ -3,7 +3,6 @@
 - Catch exceptions thrown by the argument parser and print them normally.
 - Structs or records.
 - Unions.
-- Type checking.
 - Support immediates greater than 12 bits.
 - It seems instructions are correctly encoded only if the compiler is running
   on a little endian architecture.
@@ -13,5 +12,3 @@
 - Error message with an empty file wrongly says that a ")" is expected.
 - Support any expressions for constants.
 - Name analysis should fail if there are undefined symbols.
-- type_mismatch error should get second type argument for the
-  expected type.
diff --git a/include/elna/source/result.hpp b/include/elna/source/result.hpp
index a67fcab..b75a38e 100644
--- a/include/elna/source/result.hpp
+++ b/include/elna/source/result.hpp
@@ -137,7 +137,8 @@ namespace elna::source
             argument,
             arithmetic,
             comparison,
-            condition
+            condition,
+            assignment
         };
 
         /**
diff --git a/include/elna/source/semantic.hpp b/include/elna/source/semantic.hpp
index 2bda336..55c7433 100644
--- a/include/elna/source/semantic.hpp
+++ b/include/elna/source/semantic.hpp
@@ -88,5 +88,6 @@ namespace elna::source
         void visit(constant_definition *definition) override;
         void visit(while_statement *statement) override;
         void visit(if_statement *statement) override;
+        void visit(assign_statement *statement) override;
     };
 }
diff --git a/source/semantic.cpp b/source/semantic.cpp
index 0a50ec7..789fd48 100644
--- a/source/semantic.cpp
+++ b/source/semantic.cpp
@@ -305,6 +305,19 @@ namespace elna::source
         statement->body().accept(this);
     }
 
+    void type_analysis_visitor::visit(assign_statement *statement)
+    {
+        statement->rvalue().accept(this);
+        auto lvalue_info = std::dynamic_pointer_cast<typed_info>(this->table->lookup(statement->lvalue()));
+
+        if (statement->rvalue().data_type != nullptr && lvalue_info->type() == statement->rvalue().data_type)
+        {
+            auto new_error = std::make_unique<type_mismatch>(statement->rvalue().data_type,
+                    type_mismatch::operation::assignment, this->filename, statement->position());
+            m_errors.push_back(std::move(new_error));
+        }
+    }
+
     const std::list<std::unique_ptr<error>>& type_analysis_visitor::errors() const noexcept
     {
         return m_errors;