diff --git a/src/processor/instructions/instructions.rs b/src/processor/instructions/instructions.rs
index 8683d62..970ad71 100644
--- a/src/processor/instructions/instructions.rs
+++ b/src/processor/instructions/instructions.rs
@@ -20,25 +20,15 @@ impl CPU {
     }
 
     pub(crate) fn inc(&mut self, reg: Reg8) {
-        let result = self.reg.get_8(reg).wrapping_add(0x1);
-        self.clear_flag(Flags::NSubtract);
-        self.set_or_clear_flag(Flags::Zero, result == 0x0);
-        self.set_or_clear_flag(
-            Flags::HalfCarry,
-            (((self.reg.get_8(reg) & 0xF).wrapping_add(0x1 & 0xF)) & 0x10) == 0x10,
-        );
-        self.reg.set_8(reg, result);
+        let result = self.reg.get_8(reg);
+        let val = self.inc_raw(result);
+        self.reg.set_8(reg, val);
     }
 
     pub(crate) fn dec(&mut self, reg: Reg8) {
-        let result = self.reg.get_8(reg).wrapping_sub(0x1);
-        self.set_flag(Flags::NSubtract);
-        self.set_or_clear_flag(Flags::Zero, result == 0x0);
-        self.set_or_clear_flag(
-            Flags::HalfCarry,
-            (((self.reg.get_8(reg) & 0xF).wrapping_sub(0x1 & 0xF)) & 0x10) == 0x10,
-        );
-        self.reg.set_8(reg, result);
+        let result = self.reg.get_8(reg);
+        let val = self.dec_raw(result);
+        self.reg.set_8(reg, val);
     }
 
     pub(crate) fn inc_pair(&mut self, val: u16) -> u16 {
diff --git a/src/processor/instructions/primitives.rs b/src/processor/instructions/primitives.rs
index 4faf6cc..94809d9 100644
--- a/src/processor/instructions/primitives.rs
+++ b/src/processor/instructions/primitives.rs
@@ -79,7 +79,7 @@ impl CPU {
         }
     }
 
-    pub(crate) fn is_flag(&mut self, flag: Flags) -> bool {
+    pub(crate) fn is_flag(&self, flag: Flags) -> bool {
         get_bit(self.reg.af.get_low(), flag as u8)
     }
 
@@ -167,4 +167,26 @@ impl CPU {
         );
         return result;
     }
+
+    pub(crate) fn dec_raw(&mut self, val: u8) -> u8 {
+        let result = val.wrapping_sub(0x1);
+        self.set_flag(Flags::NSubtract);
+        self.set_or_clear_flag(Flags::Zero, result == 0x0);
+        self.set_or_clear_flag(
+            Flags::HalfCarry,
+            (((val & 0xF).wrapping_sub(0x1 & 0xF)) & 0x10) == 0x10,
+        );
+        result
+    }
+
+    pub(crate) fn inc_raw(&mut self, val: u8) -> u8 {
+        let result = val.wrapping_add(0x1);
+        self.clear_flag(Flags::NSubtract);
+        self.set_or_clear_flag(Flags::Zero, result == 0x0);
+        self.set_or_clear_flag(
+            Flags::HalfCarry,
+            (((val & 0xF).wrapping_add(0x1 & 0xF)) & 0x10) == 0x10,
+        );
+        result
+    }
 }