diff --git a/cpp/vm.cpp b/cpp/vm.cpp
index 0448a25..2f5999f 100644
--- a/cpp/vm.cpp
+++ b/cpp/vm.cpp
@@ -128,7 +128,7 @@ void VM::init_regs(void) {
 INSTRUCTIONS IMPLEMENTATIONS
 */
 
-void VM::exec_movi(void) {
+bool VM::exec_movi(void) {
   /*
   MOVI R0, 0x2400 | R0 = 0x2400
   */
@@ -137,11 +137,15 @@ void VM::exec_movi(void) {
   dst = as.code[regs[IP] + 1];
   imm = *((uint16_t *)&as.code[regs[IP] + 2]);
   DBG_INFO(("MOVI %s, 0x%x\n", reg_name(dst), imm));
+  if (dst == IP) {
+    DBG_ERROR(("Can't MOVI to IP!\n"));
+    return false;
+  }
   regs[dst] = imm;
-  return;
+  return true;
 }
 
-void VM::exec_movr(void) {
+bool VM::exec_movr(void) {
   /*
   MOVR R1, R0 | R1 = R0
   ---------------------
@@ -151,11 +155,15 @@ void VM::exec_movr(void) {
   dst = as.code[regs[IP] + 1] >> 4;
   src = as.code[regs[IP] + 1] & 0b00001111;
   DBG_INFO(("MOVR %s, %s\n", reg_name(dst), reg_name(src)));
+  if (dst == IP || src == IP) {
+    DBG_ERROR(("Can't MOVR IP!\n"));
+    return false;
+  }
   regs[dst] = regs[src];
-  return;
+  return true;
 }
 
-void VM::exec_getm(void) {
+bool VM::exec_getm(void) {
   /*
   GETM R0, 0x1000 | R0 = data[0x1000]
   */
@@ -165,10 +173,10 @@ void VM::exec_getm(void) {
   src = *((uint16_t *)&as.code[regs[IP] + 2]);
   DBG_INFO(("GETM %s, 0x%x\n", reg_name(dst), src));
   regs[dst] = *((uint16_t *)&as.data[src]);
-  return;
+  return true;
 }
 
-void VM::exec_putm(void) {
+bool VM::exec_putm(void) {
   /*
   PUTM 0x1000, R0 | data[0x1000] = R0
   */
@@ -178,10 +186,10 @@ void VM::exec_putm(void) {
   src = as.code[regs[IP] + 3];
   DBG_INFO(("PUTM 0x%x 0x%x\n", dst, src));
   *((uint16_t *)&as.data[dst]) = regs[src];
-  return;
+  return true;
 }
 
-void VM::exec_addi(void) {
+bool VM::exec_addi(void) {
   /*
   ADDI R0, 0x2 | R0 += 2
   */
@@ -192,7 +200,7 @@ void VM::exec_addi(void) {
   src = *((uint16_t *)&as.code[regs[IP] + 2]);
   DBG_INFO(("ADDI 0x%x 0x%x\n", dst, src));
   regs[dst] += src;
-  return;
+  return true;
 }
 
 void VM::run(void) {
diff --git a/cpp/vm.h b/cpp/vm.h
index 921a180..d795616 100644
--- a/cpp/vm.h
+++ b/cpp/vm.h
@@ -53,12 +53,12 @@ private:
   /*
   IMPLEMENTATIONS
   */
-  void exec_movi(void);
-  void exec_movr(void);
-  void exec_movm(void);
-  void exec_getm(void);
-  void exec_putm(void);
-  void exec_addi(void);
+  bool exec_movi(void);
+  bool exec_movr(void);
+  bool exec_movm(void);
+  bool exec_getm(void);
+  bool exec_putm(void);
+  bool exec_addi(void);
 
 public:
   VM();
diff --git a/python/assembler.py b/python/assembler.py
index 1e474e4..f8f8e03 100644
--- a/python/assembler.py
+++ b/python/assembler.py
@@ -26,9 +26,9 @@ op_names = ["MOVI",
 
 reg_names = ["R0", "R1", "R2", "R3", "S0", "S1", "S2", "S3", "IP", "BP", "SP"]
 section_names = ["DATA:", "CODE:", "STACK:"]
-section_flags = {s: i + 1 for i, s in enumerate(section_names)}
-ops = {s: i for i, s in enumerate(op_names)}
-regs = {s: i for i, s in enumerate(reg_names)}
+section_flags = {s.casefold(): i + 1 for i, s in enumerate(section_names)}
+ops = {s.casefold(): i for i, s in enumerate(op_names)}
+regs = {s.casefold(): i for i, s in enumerate(reg_names)}
 
 assembled = bytearray()
 
@@ -58,14 +58,14 @@ def to_uint16(data):
 
 
 def is_reg(data):
-    if data not in reg_names:
+    if data not in [rn.casefold() for rn in reg_names]:
         return False
     return True
 
 
 def movi(op, dst, src):
     global assembled
-    if (is_reg(dst)):
+    if (is_reg(dst) and dst is not "ip"):
         op_val = to_uint8(ops[op])
         dst_val = to_uint8(regs[dst])
         src_val = to_uint16(src)
@@ -86,14 +86,14 @@ def assemble_code(line):
     global assembled
     sys.stdout.write("CODE: ")
     instruction = [x for x in re.split('\W', line) if x]
-    op_name = instruction[0]
+    op_name = instruction[0].casefold()
 
-    if op_name not in op_names:
+    if op_name not in [on.casefold() for on in op_names]:
         sys.stderr.write(
             "ERROR WHILE ASSEMBLING UNKNOWN OPERATION: {}\n".format(op_name))
         return False
     sys.stdout.write("{} {}\n".format(op_name, ", ".join(instruction[1::])))
-    if op_name == "MOVI":
+    if op_name == "movi":
         movi(op_name, instruction[1], instruction[2])
     return True
 
@@ -110,16 +110,16 @@ def main():
         return
 
     with open(sys.argv[1], 'r') as f:
-        gen = (line.strip("\n") for line in f if line != "\n")
+        gen = (line.casefold().strip("\n") for line in f if line != "\n")
         flag = None
 
         for line in gen:
-            if line.startswith(tuple(section_names)):
+            if line.startswith(tuple([sn.casefold() for sn in section_names])):
                 flag = section_flags[line]
                 continue
-            if flag == section_flags["DATA:"]:
+            if flag == section_flags["data:"]:
                 assemble_data(line)
-            elif flag == section_flags["CODE:"]:
+            elif flag == section_flags["code:"]:
                 assemble_code(line)
         if not flag:
             sys.stderr.write("Nothing was assembled! Did you use the section delimiters?\n")