diff --git a/build.sh b/build.sh
index 1df1dd2..68d2457 100755
--- a/build.sh
+++ b/build.sh
@@ -35,7 +35,7 @@ gcc -c src/common/executable.c -o temp/common/executable.o $FLAGS
 mkdir temp/runtime
 gcc -c src/runtime/runtime_error.c -o temp/runtime/runtime_error.o $FLAGS
 gcc -c src/runtime/runtime.c 	   -o temp/runtime/runtime.o       $FLAGS
-gcc -c src/runtime/builtins.c 	   -o temp/runtime/builtins.o      $FLAGS
+gcc -c src/runtime/o_builtins.c    -o temp/runtime/o_builtins.o    $FLAGS
 gcc -c src/runtime/o_nfunc.c       -o temp/runtime/o_nfunc.o       $FLAGS
 gcc -c src/runtime/o_func.c        -o temp/runtime/o_func.o        $FLAGS
 
@@ -80,7 +80,7 @@ gcc src/main.c src/debug.c \
 	temp/objects/o_string.o \
 	temp/runtime/runtime.o \
 	temp/runtime/runtime_error.o \
-	temp/runtime/builtins.o \
+	temp/runtime/o_builtins.o \
 	temp/runtime/o_nfunc.o \
 	temp/runtime/o_func.o \
 	temp/common/executable.o \
diff --git a/src/main.c b/src/main.c
index c6f5056..5104b8c 100644
--- a/src/main.c
+++ b/src/main.c
@@ -217,16 +217,6 @@ int main(int argc, char **argv)
 
 					RuntimeError error;
 					RuntimeError_Init(&error, runtime);
-
-					if(!add_builtins(runtime, (Error*) &error))
-						{
-							fprintf(stderr, "Couldn't load builtins: %s\n", error.base.message);
-							Debug_Free(dbg);
-							Source_Free(src);
-							Executable_Free(exe);
-							RuntimeError_Free(&error);
-							return 1;
-						}
 					
 					Object *result = run(runtime, (Error*) &error, exe, 0, NULL, 0);
 
diff --git a/src/objects/o_string.c b/src/objects/o_string.c
index cce9084..2758620 100644
--- a/src/objects/o_string.c
+++ b/src/objects/o_string.c
@@ -14,19 +14,38 @@ static int hash(Object *self);
 static int count(Object *self);
 static Object *copy(Object *self, Heap *heap, Error *err);
 static void print(Object *obj, FILE *fp);
+static char *to_string(Object *self, int *size, Heap *heap, Error *err);
 static _Bool op_eql(Object *self, Object *other);
 
 static const Type t_string = {
 	.base = (Object) { .type = &t_type, .flags = Object_STATIC },
 	.name = "string",
-	.size = sizeof (StringObject),
+	.atomic = ATMTP_STRING,
+	.size = sizeof(StringObject),
 	.hash = hash,
 	.count = count,
 	.copy = copy,
 	.print = print,
+	.to_string = to_string,
 	.op_eql = op_eql,
 };
 
+static char *to_string(Object *self, int *size, Heap *heap, Error *err)
+{
+	assert(self != NULL);
+	assert(self->type == &t_string);
+
+	(void) heap;
+	(void) err;
+
+	StringObject *s = (StringObject*) self;
+
+	if(size)
+		*size = s->size;
+
+	return s->body;
+}
+
 Object *Object_FromString(const char *str, int len, Heap *heap, Error *error)
 {
 	assert(str != NULL);
diff --git a/src/objects/objects.c b/src/objects/objects.c
index a65082b..efa36f3 100644
--- a/src/objects/objects.c
+++ b/src/objects/objects.c
@@ -10,7 +10,7 @@ const Type t_type = {
 
 const char *Object_GetName(const Object *obj)
 {
-	assert(obj);
+	assert(obj != NULL);
 
 	const Type *type = Object_GetType(obj);
 	assert(type);
@@ -23,15 +23,15 @@ const char *Object_GetName(const Object *obj)
 
 const Type *Object_GetType(const Object *obj)
 {
-	assert(obj);
-	assert(obj->type);
+	assert(obj != NULL);
+	assert(obj->type != NULL);
 	return obj->type;
 }
 
 unsigned int Object_GetSize(const Object *obj, Error *err)
 {
-	assert(err);
-	assert(obj);
+	assert(err != NULL);
+	assert(obj != NULL);
 
 	const Type *type = Object_GetType(obj);
 	assert(type);
@@ -41,8 +41,8 @@ unsigned int Object_GetSize(const Object *obj, Error *err)
 
 unsigned int Object_GetDeepSize(const Object *obj, Error *err)
 {
-	assert(err);
-	assert(obj);
+	assert(err != NULL);
+	assert(obj != NULL);
 
 	const Type *type = Object_GetType(obj);
 	assert(type);
@@ -58,10 +58,10 @@ unsigned int Object_GetDeepSize(const Object *obj, Error *err)
 
 int Object_Hash(Object *obj, Error *err)
 {
-	assert(obj);
+	assert(obj != NULL);
 
 	const Type *type = Object_GetType(obj);
-	assert(type);
+	assert(type != NULL);
 
 	if(type->hash == NULL)
 		{
@@ -74,11 +74,11 @@ int Object_Hash(Object *obj, Error *err)
 
 Object *Object_Copy(Object *obj, Heap *heap, Error *err)
 {
-	assert(err);
-	assert(obj);
+	assert(err != NULL);
+	assert(obj != NULL);
 
 	const Type *type = Object_GetType(obj);
-	assert(type);
+	assert(type != NULL);
 
 	if(type->copy == NULL)
 		{
@@ -245,6 +245,13 @@ _Bool Object_IsFloat(Object *obj)
 	return obj->type->atomic == ATMTP_FLOAT;
 }
 
+_Bool Object_IsString(Object *obj)
+{
+	assert(obj != NULL);
+	assert(obj->type != NULL);
+	return obj->type->atomic == ATMTP_STRING;
+}
+
 long long int Object_ToInt(Object *obj, Error *err)
 {
 	assert(err);
@@ -314,6 +321,29 @@ double Object_ToFloat(Object *obj, Error *err)
 	return type->to_float(obj, err);
 }
 
+const char *Object_ToString(Object *obj, int *size, Heap *heap, Error *err)
+{
+	assert(err != NULL);
+	assert(obj != NULL);
+
+	if(!Object_IsString(obj))
+		{
+			Error_Report(err, 0, "Object is not a string");
+			return NULL;
+		}
+
+	const Type *type = Object_GetType(obj);
+	assert(type);
+
+	if(type->to_string == NULL)
+		{
+			Error_Report(err, 0, "Object %s doesn't implement %s", Object_GetName(obj), __func__);
+			return NULL;
+		}
+
+	return type->to_string(obj, size, heap, err);
+}
+
 _Bool Object_Compare(Object *obj1, Object *obj2, Error *error)
 {
 	assert(obj1 != NULL);
diff --git a/src/objects/objects.h b/src/objects/objects.h
index e946905..4198aef 100644
--- a/src/objects/objects.h
+++ b/src/objects/objects.h
@@ -18,6 +18,7 @@ typedef enum {
 	ATMTP_INT,
 	ATMTP_BOOL,
 	ATMTP_FLOAT,
+	ATMTP_STRING,
 } AtomicType;
 
 struct Type {
@@ -94,10 +95,12 @@ Object*		 Object_FromString(const char *str, int len, Heap *heap, Error *error);
 _Bool		 Object_IsInt  (Object *obj);
 _Bool		 Object_IsBool (Object *obj);
 _Bool		 Object_IsFloat(Object *obj);
+_Bool		 Object_IsString(Object *obj);
 
 long long int Object_ToInt  (Object *obj, Error *err);
 _Bool 		  Object_ToBool (Object *obj, Error *err);
 double		  Object_ToFloat(Object *obj, Error *err);
+const char	 *Object_ToString(Object *obj, int *size, Heap *heap, Error *err);
 
 _Bool 		  Object_Compare(Object *obj1, Object *obj2, Error *error);
 
diff --git a/src/runtime/builtins.c b/src/runtime/builtins.c
deleted file mode 100644
index 98cd7c8..0000000
--- a/src/runtime/builtins.c
+++ /dev/null
@@ -1,79 +0,0 @@
-#include <assert.h>
-#include "runtime.h"
-
-static Object *bin_print(Runtime *runtime, Object **argv, unsigned int argc, Error *error)
-{
-	for(int i = 0; i < (int) argc; i += 1)
-		Object_Print(argv[i], stdout);
-
-	return Object_NewNone(Runtime_GetHeap(runtime), error);
-}
-
-static Object *bin_count(Runtime *runtime, Object **argv, unsigned int argc, Error *error)
-{
-	assert(argc == 1);
-
-	int n = Object_Count(argv[0], error);
-
-	if(error->occurred)
-		return NULL;
-
-	return Object_FromInt(n, Runtime_GetHeap(runtime), error);
-}
-
-static Object *bin_assert(Runtime *runtime, Object **argv, unsigned int argc, Error *error)
-{
-	assert(argc == 1);
-
-	if(Object_ToBool(argv[0], error))
-		{
-			return Object_NewNone(Runtime_GetHeap(runtime), error);
-		}
-	else
-		{
-			if(!error->occurred)
-				Error_Report(error, 0, "Assertion failed");
-			return NULL;
-		}
-}
-
-typedef struct {
-	const char *name;
-	int 		argc;
-	Object *(*callback)(Runtime*, Object**, unsigned int, Error*);
-} BuiltinNativeFunctions;
-
-BuiltinNativeFunctions builtins[] = {
-	{"print",  -1, bin_print},
-	{"count",   1, bin_count},
-	{"assert",  1, bin_assert},
-};
-
-_Bool add_builtins(Runtime *runtime, Error *error)
-{
-	Heap *heap = Runtime_GetHeap(runtime);
-	assert(heap != NULL);
-
-	Object *dest = Runtime_GetBuiltins(runtime, error);
-
-	if(dest == NULL)
-		return 0;
-
-	for(int i = 0; (unsigned int) i < sizeof(builtins) / sizeof(builtins[0]); i += 1)
-		{
-			Object *name = Object_FromString(builtins[i].name, -1, heap, error);
-
-			if(name == NULL)
-				return 0;
-
-			Object *func = Object_FromNativeFunction(runtime, builtins[i].callback, builtins[i].argc, heap, error);
-		
-			if(func == NULL)
-				return NULL;
-		
-			if(!Object_Insert(dest, name, func, heap, error))
-				return 0;
-		}
-
-	return 1;
-}
\ No newline at end of file
diff --git a/src/runtime/o_builtins.c b/src/runtime/o_builtins.c
new file mode 100644
index 0000000..b064db5
--- /dev/null
+++ b/src/runtime/o_builtins.c
@@ -0,0 +1,131 @@
+#include <stdint.h>
+#include <string.h>
+#include <assert.h>
+#include "runtime.h"
+#include "../utils/defs.h"
+
+static Object *select(Object *self, Object *key, Heap *heap, Error *err);
+static int      count(Object *self);
+
+static Object *bin_print (Runtime *runtime, Object **argv, unsigned int argc, Error *error);
+static Object *bin_count (Runtime *runtime, Object **argv, unsigned int argc, Error *error);
+static Object *bin_assert(Runtime *runtime, Object **argv, unsigned int argc, Error *error);
+
+typedef struct {
+	Object base;
+	Runtime *runtime;
+} BuiltinsMapOjbect;
+
+static const Type t_builtins_map = {
+	.base = (Object) { .type = &t_type, .flags = Object_STATIC },
+	.name = "builtins map",
+	.size = sizeof(BuiltinsMapOjbect),
+	.select = select,
+	.count = count,
+	.print = NULL,
+};
+
+static Object *select(Object *self, Object *key, Heap *heap, Error *err)
+{
+	BuiltinsMapOjbect *bm = (BuiltinsMapOjbect*) self;
+
+	if(!Object_IsString(key))
+		{
+			Error_Report(err, 0, "Non string key");
+			return NULL;
+		}
+
+	int         n;
+	const char *s;
+
+	s = Object_ToString(key, &n, heap, err);
+
+	if(s == NULL)
+		return NULL;
+
+	#define PAIR(p, q) \
+		(((uint64_t) (p) << 32) | (uint32_t) (q))
+
+	switch(PAIR(n, s[0]))
+		{
+			case PAIR(sizeof("count")-1, 'c'):
+			{
+				if(!strcmp(s, "count"))
+					return Object_FromNativeFunction(bm->runtime, bin_count, 1, heap, err);
+				return NULL;
+			}
+
+			case PAIR(sizeof("print")-1, 'p'):
+			{
+				if(!strcmp(s, "print"))
+					return Object_FromNativeFunction(bm->runtime, bin_print, -1, heap, err);
+				return NULL;
+			}
+
+			case PAIR(sizeof("assert")-1, 'a'):
+			{
+				if(!strcmp(s, "assert"))
+					return Object_FromNativeFunction(bm->runtime, bin_assert, -1, heap, err);
+				return NULL;
+			}
+			
+			default: NULL;
+		}
+
+	UNREACHABLE;
+	return NULL;
+}
+
+static int count(Object *self)
+{
+	(void) self;
+	return 3;
+}
+
+Object *Object_NewBuiltinsMap(Runtime *runtime, Heap *heap, Error *err)
+{
+	BuiltinsMapOjbect *bm = (BuiltinsMapOjbect*) Heap_Malloc(heap, &t_builtins_map, err);
+
+	if(bm == NULL)
+		return NULL;
+
+	bm->runtime = runtime;
+	
+	return (Object*) bm;
+}
+
+static Object *bin_print(Runtime *runtime, Object **argv, unsigned int argc, Error *error)
+{
+	for(int i = 0; i < (int) argc; i += 1)
+		Object_Print(argv[i], stdout);
+
+	return Object_NewNone(Runtime_GetHeap(runtime), error);
+}
+
+static Object *bin_count(Runtime *runtime, Object **argv, unsigned int argc, Error *error)
+{
+	assert(argc == 1);
+
+	int n = Object_Count(argv[0], error);
+
+	if(error->occurred)
+		return NULL;
+
+	return Object_FromInt(n, Runtime_GetHeap(runtime), error);
+}
+
+static Object *bin_assert(Runtime *runtime, Object **argv, unsigned int argc, Error *error)
+{
+	assert(argc == 1);
+
+	if(Object_ToBool(argv[0], error))
+		{
+			return Object_NewNone(Runtime_GetHeap(runtime), error);
+		}
+	else
+		{
+			if(!error->occurred)
+				Error_Report(error, 0, "Assertion failed");
+			return NULL;
+		}
+}
\ No newline at end of file
diff --git a/src/runtime/runtime.c b/src/runtime/runtime.c
index fa6ffb6..08ca799 100644
--- a/src/runtime/runtime.c
+++ b/src/runtime/runtime.c
@@ -104,8 +104,11 @@ void Runtime_Free(Runtime *runtime)
 Object *Runtime_GetBuiltins(Runtime *runtime, Error *error)
 {
 	if(runtime->builtins == NULL)
-		runtime->builtins = Object_NewMap(-1, runtime->heap, error);
-
+		{
+			runtime->builtins = Object_NewBuiltinsMap(runtime, Runtime_GetHeap(runtime), error);
+			if(runtime->builtins == NULL)
+				return NULL;
+		}
 	return runtime->builtins;
 }
 
@@ -790,8 +793,13 @@ static _Bool step(Runtime *runtime, Error *error)
 					{
 						// Variable not defined locally.
 
-						if(runtime->builtins != NULL)
-							obj = Object_Select(runtime->builtins, key, runtime->heap, error);
+						Object *builtins = Runtime_GetBuiltins(runtime, error);
+
+						if(builtins == NULL)
+							// Failed to create builtins map.
+							return 0;
+
+						obj = Object_Select(runtime->builtins, key, runtime->heap, error);
 
 						if(obj == NULL)
 							{
diff --git a/src/runtime/runtime.h b/src/runtime/runtime.h
index ca877f9..1a2949a 100644
--- a/src/runtime/runtime.h
+++ b/src/runtime/runtime.h
@@ -22,9 +22,9 @@ Snapshot *Snapshot_New(Runtime *runtime);
 void 	  Snapshot_Free(Snapshot *snapshot);
 void 	  Snapshot_Print(Snapshot *snapshot, FILE *fp);
 
-_Bool add_builtins(Runtime *runtime, Error *error);
 Object *run(Runtime *runtime, Error *error, Executable *exe, int index, Object **argv, int argc);
 
+Object *Object_NewBuiltinsMap(Runtime *runtime, Heap *heap, Error *err);
 Object*	Object_FromNativeFunction(Runtime *runtime, Object *(*callback)(Runtime*, Object**, unsigned int, Error*), int argc, Heap *heap, Error *error);
 Object* Object_FromNojaFunction(Runtime *runtime, Executable *exe, int index, int argc, Heap *heap, Error *error);
 #endif
\ No newline at end of file