diff --git a/cli/http_util.rs b/cli/http_util.rs
index bf302f7b22..72aaee6827 100644
--- a/cli/http_util.rs
+++ b/cli/http_util.rs
@@ -44,12 +44,9 @@ pub fn create_http_client(ca_file: Option<&str>) -> Result<Client, ErrBox> {
     builder = builder.add_root_certificate(cert);
   }
 
-  builder.build().map_err(|_| {
-    ErrBox::from(io::Error::new(
-      io::ErrorKind::Other,
-      "Unable to build http client".to_string(),
-    ))
-  })
+  builder
+    .build()
+    .map_err(|_| ErrBox::error("Unable to build http client"))
 }
 /// Construct the next uri based on base uri and location header fragment
 /// See <https://tools.ietf.org/html/rfc3986#section-4.2>
diff --git a/cli/module_graph.rs b/cli/module_graph.rs
index 7cbd4cfcc7..f7cfe42266 100644
--- a/cli/module_graph.rs
+++ b/cli/module_graph.rs
@@ -76,8 +76,10 @@ fn validate_no_file_from_remote(
         match specifier_url.scheme() {
           "http" | "https" => {}
           _ => {
-            let e = ErrBox::new("PermissionDenied",
-              "Remote modules are not allowed to statically import local modules. Use dynamic import instead.".to_string()
+            let e = ErrBox::new(
+              "PermissionDenied",
+              "Remote modules are not allowed to statically import local \
+              modules. Use dynamic import instead.",
             );
             return Err(err_with_location(e, maybe_location));
           }
diff --git a/cli/ops/dispatch_minimal.rs b/cli/ops/dispatch_minimal.rs
index b0dc7ad8a0..20e8160fff 100644
--- a/cli/ops/dispatch_minimal.rs
+++ b/cli/ops/dispatch_minimal.rs
@@ -89,7 +89,7 @@ fn test_error_record() {
     arg: -1,
     error_len: 11,
     error_class: b"BadResource",
-    error_message: "Error".to_string().as_bytes().to_owned(),
+    error_message: b"Error".to_vec(),
   };
   let buf: Buf = err_record.into();
   assert_eq!(buf, expected.into_boxed_slice());
diff --git a/cli/ops/fs.rs b/cli/ops/fs.rs
index 00736b813c..28b2a7e55c 100644
--- a/cli/ops/fs.rs
+++ b/cli/ops/fs.rs
@@ -199,9 +199,7 @@ fn op_seek(
     let mut resource_table = resource_table.borrow_mut();
     let pos = std_file_resource(&mut resource_table, rid, |r| match r {
       Ok(std_file) => std_file.seek(seek_from).map_err(ErrBox::from),
-      Err(_) => Err(ErrBox::type_error(
-        "cannot seek on this type of resource".to_string(),
-      )),
+      Err(_) => Err(ErrBox::type_error("cannot seek on this type of resource")),
     })?;
     Ok(JsonOp::Sync(json!(pos)))
   } else {
@@ -211,9 +209,9 @@ fn op_seek(
       let mut resource_table = resource_table.borrow_mut();
       let pos = std_file_resource(&mut resource_table, rid, |r| match r {
         Ok(std_file) => std_file.seek(seek_from).map_err(ErrBox::from),
-        Err(_) => Err(ErrBox::type_error(
-          "cannot seek on this type of resource".to_string(),
-        )),
+        Err(_) => {
+          Err(ErrBox::type_error("cannot seek on this type of resource"))
+        }
       })?;
       Ok(json!(pos))
     };
@@ -245,9 +243,7 @@ fn op_fdatasync(
     let mut resource_table = resource_table.borrow_mut();
     std_file_resource(&mut resource_table, rid, |r| match r {
       Ok(std_file) => std_file.sync_data().map_err(ErrBox::from),
-      Err(_) => Err(ErrBox::type_error(
-        "cannot sync this type of resource".to_string(),
-      )),
+      Err(_) => Err(ErrBox::type_error("cannot sync this type of resource")),
     })?;
     Ok(JsonOp::Sync(json!({})))
   } else {
@@ -255,9 +251,7 @@ fn op_fdatasync(
       let mut resource_table = resource_table.borrow_mut();
       std_file_resource(&mut resource_table, rid, |r| match r {
         Ok(std_file) => std_file.sync_data().map_err(ErrBox::from),
-        Err(_) => Err(ErrBox::type_error(
-          "cannot sync this type of resource".to_string(),
-        )),
+        Err(_) => Err(ErrBox::type_error("cannot sync this type of resource")),
       })?;
       Ok(json!({}))
     };
@@ -289,9 +283,7 @@ fn op_fsync(
     let mut resource_table = resource_table.borrow_mut();
     std_file_resource(&mut resource_table, rid, |r| match r {
       Ok(std_file) => std_file.sync_all().map_err(ErrBox::from),
-      Err(_) => Err(ErrBox::type_error(
-        "cannot sync this type of resource".to_string(),
-      )),
+      Err(_) => Err(ErrBox::type_error("cannot sync this type of resource")),
     })?;
     Ok(JsonOp::Sync(json!({})))
   } else {
@@ -299,9 +291,7 @@ fn op_fsync(
       let mut resource_table = resource_table.borrow_mut();
       std_file_resource(&mut resource_table, rid, |r| match r {
         Ok(std_file) => std_file.sync_all().map_err(ErrBox::from),
-        Err(_) => Err(ErrBox::type_error(
-          "cannot sync this type of resource".to_string(),
-        )),
+        Err(_) => Err(ErrBox::type_error("cannot sync this type of resource")),
       })?;
       Ok(json!({}))
     };
@@ -333,9 +323,7 @@ fn op_fstat(
     let mut resource_table = resource_table.borrow_mut();
     let metadata = std_file_resource(&mut resource_table, rid, |r| match r {
       Ok(std_file) => std_file.metadata().map_err(ErrBox::from),
-      Err(_) => Err(ErrBox::type_error(
-        "cannot stat this type of resource".to_string(),
-      )),
+      Err(_) => Err(ErrBox::type_error("cannot stat this type of resource")),
     })?;
     Ok(JsonOp::Sync(get_stat_json(metadata).unwrap()))
   } else {
@@ -344,9 +332,9 @@ fn op_fstat(
       let metadata =
         std_file_resource(&mut resource_table, rid, |r| match r {
           Ok(std_file) => std_file.metadata().map_err(ErrBox::from),
-          Err(_) => Err(ErrBox::type_error(
-            "cannot stat this type of resource".to_string(),
-          )),
+          Err(_) => {
+            Err(ErrBox::type_error("cannot stat this type of resource"))
+          }
         })?;
       Ok(get_stat_json(metadata).unwrap())
     };
@@ -879,7 +867,7 @@ fn op_symlink(
         Some(options) => match options._type.as_ref() {
           "file" => symlink_file(&oldpath, &newpath)?,
           "dir" => symlink_dir(&oldpath, &newpath)?,
-          _ => return Err(ErrBox::type_error("unsupported type".to_string())),
+          _ => return Err(ErrBox::type_error("unsupported type")),
         },
         None => {
           let old_meta = std::fs::metadata(&oldpath);
@@ -955,9 +943,9 @@ fn op_ftruncate(
     let mut resource_table = resource_table.borrow_mut();
     std_file_resource(&mut resource_table, rid, |r| match r {
       Ok(std_file) => std_file.set_len(len).map_err(ErrBox::from),
-      Err(_) => Err(ErrBox::type_error(
-        "cannot truncate this type of resource".to_string(),
-      )),
+      Err(_) => {
+        Err(ErrBox::type_error("cannot truncate this type of resource"))
+      }
     })?;
     Ok(JsonOp::Sync(json!({})))
   } else {
@@ -965,9 +953,9 @@ fn op_ftruncate(
       let mut resource_table = resource_table.borrow_mut();
       std_file_resource(&mut resource_table, rid, |r| match r {
         Ok(std_file) => std_file.set_len(len).map_err(ErrBox::from),
-        Err(_) => Err(ErrBox::type_error(
-          "cannot truncate this type of resource".to_string(),
-        )),
+        Err(_) => {
+          Err(ErrBox::type_error("cannot truncate this type of resource"))
+        }
       })?;
       Ok(json!({}))
     };
diff --git a/cli/ops/io.rs b/cli/ops/io.rs
index 6b97f542cf..14d32a39b7 100644
--- a/cli/ops/io.rs
+++ b/cli/ops/io.rs
@@ -117,7 +117,7 @@ fn get_stdio_stream(
 }
 
 fn no_buffer_specified() -> ErrBox {
-  ErrBox::type_error("no buffer specified".to_string())
+  ErrBox::type_error("no buffer specified")
 }
 
 #[cfg(unix)]
@@ -262,9 +262,9 @@ pub fn op_read(
             .map(|n: usize| n as i32)
             .map_err(ErrBox::from)
         }
-        Err(_) => Err(ErrBox::type_error(
-          "sync read not allowed on this resource".to_string(),
-        )),
+        Err(_) => {
+          Err(ErrBox::type_error("sync read not allowed on this resource"))
+        }
       })
     })
   } else {
@@ -383,9 +383,9 @@ pub fn op_write(
             .map(|nwritten: usize| nwritten as i32)
             .map_err(ErrBox::from)
         }
-        Err(_) => Err(ErrBox::type_error(
-          "sync read not allowed on this resource".to_string(),
-        )),
+        Err(_) => {
+          Err(ErrBox::type_error("sync read not allowed on this resource"))
+        }
       })
     })
   } else {
diff --git a/cli/ops/net.rs b/cli/ops/net.rs
index 25639cb79b..d979f44aef 100644
--- a/cli/ops/net.rs
+++ b/cli/ops/net.rs
@@ -53,9 +53,7 @@ fn accept_tcp(
       let mut resource_table = resource_table.borrow_mut();
       let listener_resource = resource_table
         .get_mut::<TcpListenerResource>(rid)
-        .ok_or_else(|| {
-          ErrBox::bad_resource("Listener has been closed".to_string())
-        })?;
+        .ok_or_else(|| ErrBox::bad_resource("Listener has been closed"))?;
       let listener = &mut listener_resource.listener;
       match listener.poll_accept(cx).map_err(ErrBox::from) {
         Poll::Ready(Ok((stream, addr))) => {
@@ -142,9 +140,7 @@ fn receive_udp(
       let mut resource_table = resource_table.borrow_mut();
       let resource = resource_table
         .get_mut::<UdpSocketResource>(rid)
-        .ok_or_else(|| {
-          ErrBox::bad_resource("Socket has been closed".to_string())
-        })?;
+        .ok_or_else(|| ErrBox::bad_resource("Socket has been closed"))?;
       let socket = &mut resource.socket;
       socket
         .poll_recv_from(cx, &mut zero_copy)
@@ -216,9 +212,7 @@ fn op_datagram_send(
         let mut resource_table = resource_table.borrow_mut();
         let resource = resource_table
           .get_mut::<UdpSocketResource>(rid as u32)
-          .ok_or_else(|| {
-            ErrBox::bad_resource("Socket has been closed".to_string())
-          })?;
+          .ok_or_else(|| ErrBox::bad_resource("Socket has been closed"))?;
         resource
           .socket
           .poll_send_to(cx, &zero_copy, &addr)
diff --git a/cli/ops/net_unix.rs b/cli/ops/net_unix.rs
index d8f6c67361..e03a7ba87e 100644
--- a/cli/ops/net_unix.rs
+++ b/cli/ops/net_unix.rs
@@ -43,9 +43,7 @@ pub fn accept_unix(
     let listener_resource = {
       resource_table_
         .get_mut::<UnixListenerResource>(rid)
-        .ok_or_else(|| {
-          ErrBox::bad_resource("Listener has been closed".to_string())
-        })?
+        .ok_or_else(|| ErrBox::bad_resource("Listener has been closed"))?
     };
 
     let (unix_stream, _socket_addr) =
@@ -90,9 +88,7 @@ pub fn receive_unix_packet(
     let mut resource_table_ = resource_table.borrow_mut();
     let resource = resource_table_
       .get_mut::<UnixDatagramResource>(rid)
-      .ok_or_else(|| {
-        ErrBox::bad_resource("Socket has been closed".to_string())
-      })?;
+      .ok_or_else(|| ErrBox::bad_resource("Socket has been closed"))?;
     let (size, remote_addr) = resource.socket.recv_from(&mut zero_copy).await?;
     Ok(json!({
       "size": size,
diff --git a/cli/ops/tls.rs b/cli/ops/tls.rs
index 97dca9d90b..2d47d8ebee 100644
--- a/cli/ops/tls.rs
+++ b/cli/ops/tls.rs
@@ -371,9 +371,7 @@ fn op_accept_tls(
       let mut resource_table = resource_table.borrow_mut();
       let listener_resource = resource_table
         .get_mut::<TlsListenerResource>(rid)
-        .ok_or_else(|| {
-          ErrBox::bad_resource("Listener has been closed".to_string())
-        })?;
+        .ok_or_else(|| ErrBox::bad_resource("Listener has been closed"))?;
       let listener = &mut listener_resource.listener;
       match listener.poll_accept(cx).map_err(ErrBox::from) {
         Poll::Ready(Ok((stream, addr))) => {
diff --git a/cli/signal.rs b/cli/signal.rs
index fcc70d00ef..5c9a7d717a 100644
--- a/cli/signal.rs
+++ b/cli/signal.rs
@@ -49,7 +49,7 @@ pub fn kill(pid: i32, signal: i32) -> Result<(), ErrBox> {
       }
     }
     _ => {
-      return Err(ErrBox::type_error("unsupported signal".to_string()));
+      return Err(ErrBox::type_error("unsupported signal"));
     }
   }
   Ok(())
diff --git a/core/errors.rs b/core/errors.rs
index 3dfe5824c9..8fdcca0597 100644
--- a/core/errors.rs
+++ b/core/errors.rs
@@ -450,7 +450,7 @@ impl fmt::Debug for ErrWithV8Handle {
 mod tests {
   #[test]
   fn test_bad_resource() {
-    let err = ErrBox::bad_resource("Resource has been closed".to_string());
+    let err = ErrBox::bad_resource("Resource has been closed");
     assert_eq!(err.1, "BadResource");
     assert_eq!(err.to_string(), "Resource has been closed");
   }