diff --git a/src/inst.h b/src/inst.h
index 95baaf2..086696a 100644
--- a/src/inst.h
+++ b/src/inst.h
@@ -17,14 +17,20 @@
 
 typedef enum
 {
-  OP_PUSH_BYTE = 1,
-  OP_PUSH_WORD,
-  OP_PUSH_FLOAT,
-} op_t;
+  OP_NOOP = 0,
+
+  OP_PUSH_BYTE  = 0b0001,
+  OP_PUSH_WORD  = 0b0101,
+  OP_PUSH_FLOAT = 0b1001,
+
+  OP_HALT,
+} opcode_t;
+
+#define OPCODE_IS_PUSH(OPCODE) (((OPCODE)&1) == 1)
 
 typedef struct
 {
-  op_t opcode;
+  opcode_t opcode;
   data_t operand;
 } inst_t;
 
diff --git a/src/main.c b/src/main.c
index 9b744b2..4ccb42a 100644
--- a/src/main.c
+++ b/src/main.c
@@ -121,11 +121,10 @@ void vm_execute(vm_t *vm)
     // TODO: Error (Went past end of program)
     return;
   inst_t instruction = prog->instructions[prog->ptr];
-  // NOTE: This is ballsy; I'm essentially saying I will never use the
-  // last 2 bits unless it's a push routine
-  if ((instruction.opcode & 0b11) != 0)
+
+  // Check if opcode is PUSH_LIKE
+  if (OPCODE_IS_PUSH(instruction.opcode))
   {
-    // Possible push routines
     typedef void (*push_f)(vm_t *, data_t);
     const push_f routines[] = {[OP_PUSH_BYTE]  = vm_push_byte,
                                [OP_PUSH_WORD]  = vm_push_word,