diff --git a/tests/cbmc/proofs/s2n_stuffer_private_key_from_pem/Makefile b/tests/cbmc/proofs/s2n_stuffer_private_key_from_pem/Makefile
index 199de86856f..aa56eb79b42 100644
--- a/tests/cbmc/proofs/s2n_stuffer_private_key_from_pem/Makefile
+++ b/tests/cbmc/proofs/s2n_stuffer_private_key_from_pem/Makefile
@@ -11,8 +11,8 @@
 # implied. See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Enough to get full coverage with 7 minutes of runtime.
-MAX_BLOB_SIZE = 10
+# Enough to get full coverage with a reasonable runtime.
+MAX_BLOB_SIZE = 8
 DEFINES += -DMAX_BLOB_SIZE=$(MAX_BLOB_SIZE)
 
 CHECKFLAGS +=