diff --git a/bindings/c/src/operator.rs b/bindings/c/src/operator.rs
index 859d7a0335f3..71a1e52e68cd 100644
--- a/bindings/c/src/operator.rs
+++ b/bindings/c/src/operator.rs
@@ -173,7 +173,7 @@ pub unsafe extern "C" fn opendal_operator_new(
         }
     };
 
-    let mut map = HashMap::default();
+    let mut map = HashMap::<String, String>::default();
     if !options.is_null() {
         for (k, v) in (*options).as_ref() {
             map.insert(k.to_string(), v.to_string());
diff --git a/bindings/dotnet/src/lib.rs b/bindings/dotnet/src/lib.rs
index 0d9cee1f8d07..acfd5834a2ab 100644
--- a/bindings/dotnet/src/lib.rs
+++ b/bindings/dotnet/src/lib.rs
@@ -36,7 +36,7 @@ pub unsafe extern "C" fn blocking_operator_construct(
         Err(_) => return std::ptr::null(),
     };
 
-    let mut map = HashMap::default();
+    let mut map = HashMap::<String, String>::default();
     map.insert("root".to_string(), "/tmp".to_string());
     let op = match opendal::Operator::via_iter(scheme, map) {
         Ok(op) => op.blocking(),
diff --git a/bindings/lua/src/lib.rs b/bindings/lua/src/lib.rs
index f397a84f8d2f..d220b9c9276b 100644
--- a/bindings/lua/src/lib.rs
+++ b/bindings/lua/src/lib.rs
@@ -44,7 +44,7 @@ fn operator_new<'a>(
         return Err(LuaError::external("schema is empty"));
     }
 
-    let mut map = HashMap::default();
+    let mut map = HashMap::<String, String>::default();
     for pair in option.pairs::<String, String>() {
         let (key, value) = pair?;
         map.insert(key, value);