diff --git a/sim/mcuboot-sys/src/c.rs b/sim/mcuboot-sys/src/c.rs
index 549c48a..5f518f5 100644
--- a/sim/mcuboot-sys/src/c.rs
+++ b/sim/mcuboot-sys/src/c.rs
@@ -63,7 +63,7 @@
                                   encbuf.as_mut_ptr()) == 0 {
             return Ok(encbuf);
         }
-        return Err("Failed to encrypt buffer");
+        Err("Failed to encrypt buffer")
     }
 }
 
@@ -73,7 +73,7 @@
         if raw::kw_encrypt_(kek.as_ptr(), seckey.as_ptr(), encbuf.as_mut_ptr()) == 0 {
             return Ok(encbuf);
         }
-        return Err("Failed to encrypt buffer");
+        Err("Failed to encrypt buffer")
     }
 }