diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1dec812e8..f13b6e198 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@ Bug fixes
 ---------
 
 * The position of an undefined operation call now points to the operator instead of the first operand.
+* The `optimize` command in `rhai-repl` now works properly and cycles through `None`->`Simple`->`Full`.
 
 Deprecated API's
 ----------------
diff --git a/src/bin/rhai-repl.rs b/src/bin/rhai-repl.rs
index 025f05d45..65b826b7b 100644
--- a/src/bin/rhai-repl.rs
+++ b/src/bin/rhai-repl.rs
@@ -438,15 +438,21 @@ fn main() {
                 continue;
             }
             #[cfg(not(feature = "no_optimize"))]
-            "optimize" if optimize_level == rhai::OptimizationLevel::Simple => {
-                optimize_level = rhai::OptimizationLevel::None;
-                println!("Script optimization turned OFF.");
-                continue;
-            }
-            #[cfg(not(feature = "no_optimize"))]
             "optimize" => {
-                optimize_level = rhai::OptimizationLevel::Simple;
-                println!("Script optimization turned ON.");
+                match optimize_level {
+                    rhai::OptimizationLevel::Full => {
+                        optimize_level = rhai::OptimizationLevel::None;
+                        println!("Script optimization turned OFF.");
+                    }
+                    rhai::OptimizationLevel::Simple => {
+                        optimize_level = rhai::OptimizationLevel::Full;
+                        println!("Script optimization turned to FULL.");
+                    }
+                    _ => {
+                        optimize_level = rhai::OptimizationLevel::Simple;
+                        println!("Script optimization turned to SIMPLE.");
+                    }
+                }
                 continue;
             }
             "scope" => {