diff --git a/scripts/small.toy b/scripts/small.toy
index 1c8a0e7..fd40910 100644
--- a/scripts/small.toy
+++ b/scripts/small.toy
@@ -1 +1,4 @@
-;
\ No newline at end of file
+
+
+
+
diff --git a/source/interpreter.c b/source/interpreter.c
index b191fd8..d62aa4c 100644
--- a/source/interpreter.c
+++ b/source/interpreter.c
@@ -310,7 +310,7 @@ static bool execVarDecl(Interpreter* interpreter, bool lng) {
 		return false;
 	}
 
-	if (!setScopeVariable(interpreter->scope, identifier, parseIdentifierToValue(interpreter, popLiteralArray(&interpreter->stack)) )) {
+	if (!setScopeVariable(interpreter->scope, identifier, parseIdentifierToValue(interpreter, popLiteralArray(&interpreter->stack)), false)) {
 		printf("Incorrect type assigned to variable \"");
 		printLiteral(identifier);
 		printf("\"\n");
@@ -338,7 +338,7 @@ static bool execVarAssign(Interpreter* interpreter) {
 		return false;
 	}
 
-	if (!setScopeVariable(interpreter->scope, lhs, rhs)) {
+	if (!setScopeVariable(interpreter->scope, lhs, rhs, true)) {
 		printf("Incorrect type assigned to variable \"");
 		printLiteral(lhs);
 		printf("\"\n");
diff --git a/source/scope.c b/source/scope.c
index 90ccb46..65c11ce 100644
--- a/source/scope.c
+++ b/source/scope.c
@@ -21,6 +21,58 @@ static void freeAncestorChain(Scope* scope) {
 	FREE(Scope, scope);
 }
 
+//return false if invalid type
+static bool checkType(Literal typeLiteral, Literal value) {
+	//for any types
+	if (AS_TYPE(typeLiteral).mask == MASK_ANY) {
+		return true;
+	}
+
+	//for each type, if a mismatch is found, return false
+	if ((AS_TYPE(typeLiteral).mask & MASK_BOOLEAN) && !IS_BOOLEAN(value)) {
+		return false;
+	}
+
+	if ((AS_TYPE(typeLiteral).mask & MASK_INTEGER) && !IS_INTEGER(value)) {
+		return false;
+	}
+
+	if ((AS_TYPE(typeLiteral).mask & MASK_FLOAT) && !IS_FLOAT(value)) {
+		return false;
+	}
+
+	if ((AS_TYPE(typeLiteral).mask & MASK_STRING) && !IS_STRING(value)) {
+		return false;
+	}
+
+	if ((AS_TYPE(typeLiteral).mask & MASK_ARRAY) && IS_ARRAY(value)) {
+		//check children
+		for (int i = 0; i < AS_ARRAY(value)->count; i++) {
+			if (!checkType(((Literal*)(AS_TYPE(typeLiteral).subtypes))[0], AS_ARRAY(value)->literals[i])) {
+				return false;
+			}
+		}
+	}
+
+	if ((AS_TYPE(typeLiteral).mask & MASK_DICTIONARY) && IS_DICTIONARY(value)) {
+		//check children
+		for (int i = 0; i < AS_DICTIONARY(value)->capacity; i++) {
+			//only assigned and non-tombstoned keys
+			if (!IS_NULL(AS_DICTIONARY(value)->entries[i].key)) {
+				if (checkType(((Literal*)(AS_TYPE(typeLiteral).subtypes))[0], AS_DICTIONARY(value)->entries[i].key)) {
+					return false;
+				}
+
+				if (checkType(((Literal*)(AS_TYPE(typeLiteral).subtypes))[1], AS_DICTIONARY(value)->entries[i].value)) {
+					return false;
+				}
+			}
+		}
+	}
+
+	return true;
+}
+
 //exposed functions
 Scope* pushScope(Scope* ancestor) {
 	Scope* scope = ALLOCATE(Scope, 1);
@@ -44,7 +96,7 @@ Scope* popScope(Scope* scope) {
 
 	return ret;
 }
-#include <stdio.h>
+
 //returns false if error
 bool declareScopeVariable(Scope* scope, Literal key, Literal type) {
 	//don't redefine a variable within this scope
@@ -64,19 +116,30 @@ bool isDelcaredScopeVariable(Scope* scope, Literal key) {
 }
 
 //return false if undefined, or can't be assigned
-bool setScopeVariable(Scope* scope, Literal key, Literal value) {
+bool setScopeVariable(Scope* scope, Literal key, Literal value, bool constCheck) {
 	//dead end
 	if (scope == NULL) {
 		return false;
 	}
 
-	//TODO: type checking
-
 	//if it's not in this scope, keep searching up the chain
 	if (!existsLiteralDictionary(&scope->variables, key)) {
-		return setScopeVariable(scope->ancestor, key, value);
+		return setScopeVariable(scope->ancestor, key, value, constCheck);
 	}
 
+	//type checking
+	Literal typeLiteral = getLiteralDictionary(&scope->types, key);
+
+	if (!checkType(typeLiteral, value)) {
+		return false;
+	}
+
+	//const check
+	if (constCheck && (AS_TYPE(typeLiteral).mask & MASK_CONST)) {
+		return false;
+	}
+
+	//actually assign
 	setLiteralDictionary(&scope->variables, key, value);
 	return true;
 }
diff --git a/source/scope.h b/source/scope.h
index 3d9bd65..dddb9b1 100644
--- a/source/scope.h
+++ b/source/scope.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include "literal_array.h"
 #include "literal_dictionary.h"
 
 typedef struct Scope {
@@ -17,6 +18,6 @@ bool declareScopeVariable(Scope* scope, Literal key, Literal type);
 bool isDelcaredScopeVariable(Scope* scope, Literal key);
 
 //return false if undefined
-bool setScopeVariable(Scope* scope, Literal key, Literal value);
+bool setScopeVariable(Scope* scope, Literal key, Literal value, bool constCheck);
 bool getScopeVariable(Scope* scope, Literal key, Literal* value);