diff --git a/Vector.c b/Vector.c
index 0cdf9af2c372b0fb795fcbf99ae01f3b373c61bc..6eb91ae692e5684e1b3fb89128d0cbb91ada44e7 100644
--- a/Vector.c
+++ b/Vector.c
@@ -284,11 +284,19 @@ inline Object* Vector_get(Vector* this, int idx) {
 
 #endif
 
+#ifdef DEBUG
+
 inline int Vector_size(Vector* this) {
    assert(Vector_isConsistent(this));
    return this->items;
 }
 
+#else
+
+#define Vector_size(v_) ((v_)->items)
+
+#endif
+
 /*
 
 static void Vector_merge(Vector* this, Vector* v2) {
diff --git a/Vector.h b/Vector.h
index 9b284778470fd8a938e65b9e6b7d4f2b38ddaa29..85939bf1890c399e244e0333adc561a13f6a1e86 100644
--- a/Vector.h
+++ b/Vector.h
@@ -70,8 +70,16 @@ extern Object* Vector_get(Vector* this, int idx);
 
 #endif
 
+#ifdef DEBUG
+
 extern int Vector_size(Vector* this);
 
+#else
+
+#define Vector_size(v_) ((v_)->items)
+
+#endif
+
 /*
 
 */