diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 86264411b03..c7639d2f60f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -82,7 +82,7 @@ jobs:
       - uses: actions-rs/toolchain@v1.0.7
         id: toolchain
         with:
-          toolchain: nightly-2023-05-24
+          toolchain: nightly-2023-08-25
           profile: minimal
           override: true
       - name: Install cargo-public-api
diff --git a/aws-lc-rs/src/digest.rs b/aws-lc-rs/src/digest.rs
index 57f0039d4ed..5a4dd898c99 100644
--- a/aws-lc-rs/src/digest.rs
+++ b/aws-lc-rs/src/digest.rs
@@ -324,13 +324,13 @@ mod tests {
                         super::max_input_test(&digest::$algorithm_name);
                     }
                     #[test]
-                    #[should_panic]
+                    #[should_panic(expected = "digest update failed")]
                     fn too_long_input_test_block() {
                         super::too_long_input_test_block(&digest::$algorithm_name);
                     }
 
                     #[test]
-                    #[should_panic]
+                    #[should_panic(expected = "digest update failed")]
                     fn too_long_input_test_byte() {
                         super::too_long_input_test_byte(&digest::$algorithm_name);
                     }
diff --git a/aws-lc-rs/src/test.rs b/aws-lc-rs/src/test.rs
index 36fc80e743a..9045d3be0d1 100644
--- a/aws-lc-rs/src/test.rs
+++ b/aws-lc-rs/src/test.rs
@@ -558,7 +558,9 @@ mod tests {
     }
 
     #[test]
-    #[should_panic]
+    #[should_panic(
+        expected = "source slice length (42) does not match destination slice length (0)"
+    )]
     fn fixed_slice_random_length_mismatch() {
         let fbr = FixedSliceRandom { bytes: &[42u8; 42] };
         let _: Result<(), error::Unspecified> = fbr.fill_impl(&mut []);
@@ -579,7 +581,7 @@ mod tests {
     }
 
     #[test]
-    #[should_panic]
+    #[should_panic(expected = "index out of bounds: the len is 0 but the index is 0")]
     fn fixed_slice_sequence_random_no_remaining() {
         let fbr = FixedSliceSequenceRandom {
             bytes: &[],