diff --git a/src/Nand2Tetris/VM.hs b/src/Nand2Tetris/VM.hs
index 06b24ed..30a0d34 100644
--- a/src/Nand2Tetris/VM.hs
+++ b/src/Nand2Tetris/VM.hs
@@ -259,7 +259,8 @@ compileInstruction instr = do
       labDone <- nextLabelId
       let rest = [
             Code (A (Label "SP")),
-            Code (C [RegD] (SRegMinus1 RegM) JNone),
+            Code (C [RegA] (SRegMinus1 RegM) JNone),
+            Code (C [RegD] (SReg RegM) JNone),
             Code (A (Label labEq)),
             Code (C [] (SReg RegD) jumpType),
             Code (A (Label "SP")),
@@ -330,13 +331,13 @@ compileInstruction instr = do
                            Code (C [RegD] (SReg RegA) JNone),
                            Code (A (Label regName)),
                            Code (C [RegD] SDPlusM JNone),
-                           Code (A (Label "R15")),
+                           Code (A (Imm 15)),
                            Code (C [RegM] (SReg RegD) JNone),
 
                            Code (A (Label "SP")),
                            Code (C [RegA] (SReg RegM) JNone),
                            Code (C [RegD] (SReg RegM) JNone),
-                           Code (A (Label "R15")),
+                           Code (A (Imm 15)),
                            Code (C [RegA] (SReg RegM) JNone),
                            Code (C [RegM] (SReg RegD) JNone)
                             ]