diff --git a/compiler/noirc_frontend/src/monomorphization/mod.rs b/compiler/noirc_frontend/src/monomorphization/mod.rs
index 663731d462c..7e06b94ca5a 100644
--- a/compiler/noirc_frontend/src/monomorphization/mod.rs
+++ b/compiler/noirc_frontend/src/monomorphization/mod.rs
@@ -1038,10 +1038,10 @@ impl<'interner> Monomorphizer<'interner> {
         // since they cannot be passed from ACIR into Brillig
         if let HirType::Array(size, _) = typ {
             if let HirType::NotConstant = **size {
-                unreachable!("println does not support slices. Convert the slice to an array before passing it to println");
+                unreachable!("println and format strings do not support slices. Convert the slice to an array before passing it to println");
             }
         } else if matches!(typ, HirType::MutableReference(_)) {
-            unreachable!("println does not support mutable references.");
+            unreachable!("println and format strings do not support mutable references.");
         }
 
         let printable_type: PrintableType = typ.into();
diff --git a/docs/docs/noir/standard_library/options.md b/docs/docs/noir/standard_library/options.md
index 970c9cfbf11..a1bd4e1de5f 100644
--- a/docs/docs/noir/standard_library/options.md
+++ b/docs/docs/noir/standard_library/options.md
@@ -56,6 +56,10 @@ Returns the wrapped value if `self.is_some()`. Otherwise, returns the given defa
 
 Returns the wrapped value if `self.is_some()`. Otherwise, calls the given function to return a default value.
 
+### expect
+
+Asserts `self.is_some()` with a provided custom message and returns the contained `Some` value. The custom message is expected to be a format string.
+
 ### map
 
 If self is `Some(x)`, this returns `Some(f(x))`. Otherwise, this returns `None`.
diff --git a/noir_stdlib/src/option.nr b/noir_stdlib/src/option.nr
index 137d57f33db..cab95731d05 100644
--- a/noir_stdlib/src/option.nr
+++ b/noir_stdlib/src/option.nr
@@ -56,6 +56,12 @@ impl<T> Option<T> {
         }
     }
 
+    /// Asserts `self.is_some()` with a provided custom message and returns the contained `Some` value
+    fn expect<N, MessageTypes>(self, message: fmtstr<N, MessageTypes>) -> T {
+        assert(self.is_some(), message);
+        self._value
+    }
+
     /// If self is `Some(x)`, this returns `Some(f(x))`. Otherwise, this returns `None`.
     pub fn map<U, Env>(self, f: fn[Env](T) -> U) -> Option<U> {
         if self._is_some {
diff --git a/test_programs/compile_failure/assert_msg_runtime/Prover.toml b/test_programs/compile_failure/assert_msg_runtime/Prover.toml
new file mode 100644
index 00000000000..f28f2f8cc48
--- /dev/null
+++ b/test_programs/compile_failure/assert_msg_runtime/Prover.toml
@@ -0,0 +1,2 @@
+x = "5"
+y = "10"
diff --git a/test_programs/compile_failure/brillig_assert_msg_runtime/Prover.toml b/test_programs/compile_failure/brillig_assert_msg_runtime/Prover.toml
new file mode 100644
index 00000000000..0e5dfd5638d
--- /dev/null
+++ b/test_programs/compile_failure/brillig_assert_msg_runtime/Prover.toml
@@ -0,0 +1 @@
+x = "5"
diff --git a/test_programs/compile_failure/option_expect/Nargo.toml b/test_programs/compile_failure/option_expect/Nargo.toml
new file mode 100644
index 00000000000..1ee1215ff71
--- /dev/null
+++ b/test_programs/compile_failure/option_expect/Nargo.toml
@@ -0,0 +1,7 @@
+[package]
+name = "option_expect"
+type = "bin"
+authors = [""]
+compiler_version = ">=0.23.0"
+
+[dependencies]
\ No newline at end of file
diff --git a/test_programs/compile_failure/option_expect/src/main.nr b/test_programs/compile_failure/option_expect/src/main.nr
new file mode 100644
index 00000000000..439ce4f386e
--- /dev/null
+++ b/test_programs/compile_failure/option_expect/src/main.nr
@@ -0,0 +1,8 @@
+fn main() {
+    let inner_value = 3;
+    let none = Option::none();
+    let some = Option::some(inner_value);
+
+    assert(some.expect(f"Should have the value {inner_value}") == 3);
+    assert(none.expect(f"Should have the value {inner_value}") == 3);
+}
diff --git a/test_programs/compile_failure/option_expect_bad_input/Nargo.toml b/test_programs/compile_failure/option_expect_bad_input/Nargo.toml
new file mode 100644
index 00000000000..0555681e188
--- /dev/null
+++ b/test_programs/compile_failure/option_expect_bad_input/Nargo.toml
@@ -0,0 +1,7 @@
+[package]
+name = "option_expect_bad_input"
+type = "bin"
+authors = [""]
+compiler_version = ">=0.23.0"
+
+[dependencies]
\ No newline at end of file
diff --git a/test_programs/compile_failure/option_expect_bad_input/src/main.nr b/test_programs/compile_failure/option_expect_bad_input/src/main.nr
new file mode 100644
index 00000000000..cc93e767975
--- /dev/null
+++ b/test_programs/compile_failure/option_expect_bad_input/src/main.nr
@@ -0,0 +1,6 @@
+fn main() {
+    let inner_value = 3;
+    let some = Option::some(inner_value);
+
+    assert(some.expect("Should have the value {inner_value}") == 3);
+}
diff --git a/test_programs/compile_success_empty/option/src/main.nr b/test_programs/compile_success_empty/option/src/main.nr
index 1f879bd375f..989c8f65bf4 100644
--- a/test_programs/compile_success_empty/option/src/main.nr
+++ b/test_programs/compile_success_empty/option/src/main.nr
@@ -1,5 +1,3 @@
-use dep::std::option::Option;
-
 fn main() {
     let ten = 10; // giving this a name, to ensure that the Option functions work with closures
     let none = Option::none();
@@ -22,6 +20,8 @@ fn main() {
     assert(some.map(|x| x * 2).unwrap() == 6);
     assert(some.map(|x| x * ten).unwrap() == 30);
 
+    assert(some.expect(f"Should have a value") == 3);
+
     assert(none.map_or(0, |x| x * 2) == 0);
     assert(some.map_or(0, |x| x * 2) == 6);
     assert(none.map_or(0, |x| x * ten) == 0);