diff --git a/rust/Cargo.toml b/rust/Cargo.toml
index 52706368..39785374 100644
--- a/rust/Cargo.toml
+++ b/rust/Cargo.toml
@@ -9,3 +9,15 @@ itertools = "0.13.0"
 num-traits = "0.2.19"
 rstest = "0.21.0"
 seq-macro = "0.3.5"
+
+[profile.dev.package."*"]
+# Set the default for dependencies in Development mode.
+opt-level = 3
+debug = true
+lto = true
+
+[profile.dev]
+# Turn on a small amount of optimisation in Development mode.
+opt-level = 1
+debug = true
+lto = "thin"
diff --git a/rust/Makefile b/rust/Makefile
index 8bce11e8..f9eff54f 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -1,6 +1,5 @@
 BLUE=\033[0;34m
 NC=\033[0m # No Color
-RUSTFLAGS?="-Copt-level=2"
 
 .PHONY: help
 help:
diff --git a/rust/src/main.rs b/rust/src/main.rs
index 979733e3..c7915103 100644
--- a/rust/src/main.rs
+++ b/rust/src/main.rs
@@ -56,7 +56,7 @@ fn get_problem<'b>(n: usize) -> ProblemRef<'b> {
         20 =>  ( &20, p0020::p0020, false),
         22 =>  ( &22, p0022::p0022, false),
         24 =>  ( &24, p0024::p0024, false),
-        27 =>  ( &27, p0027::p0027, true),
+        27 =>  ( &27, p0027::p0027, false),
         34 =>  ( &34, p0034::p0034, false),
         69 =>  ( &69, p0069::p0069, false),
         76 =>  ( &76, p0076::p0076, false),