diff --git a/src/cpu.rs b/src/cpu.rs
index f468977..8c0ad08 100644
--- a/src/cpu.rs
+++ b/src/cpu.rs
@@ -323,7 +323,7 @@ mod instructions {
             Ok(())
         }
         pub fn inc16(&mut self, reg: R16) -> IResult {
-            self[reg] -= 1;
+            self[reg] += 1;
             Ok(())
         }
         pub fn dec16(&mut self, reg: R16) -> IResult {