diff --git a/src/lib.rs b/src/lib.rs
index ebd28bc..db87f0b 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -145,6 +145,7 @@ pub mod zookeeper;
 
 /// Re-exported version of `testcontainers` to avoid version conflicts
 pub use testcontainers;
+use testcontainers::CopyDataSource;
 
 #[cfg(any(feature = "postgres", feature = "mariadb", feature = "mysql"))]
 #[cfg_attr(
@@ -158,17 +159,20 @@ pub trait InitSql {
     /// # Example
     ///
     /// ```
+    /// # #[cfg(feature = "postgres")]
+    /// # {
     /// # use testcontainers_modules::postgres::Postgres;
     /// # use testcontainers_modules::InitSql;
-    /// let postgres_image =
-    ///     Postgres::default().with_init_sql("CREATE EXTENSION IF NOT EXISTS hstore;");
+    /// let postgres_image = Postgres::default()
+    ///                                .with_init_sql("CREATE EXTENSION IF NOT EXISTS hstore;".to_string().into_bytes());
+    /// # }
     /// ```
     ///
     /// ```rust,ignore
     /// # use testcontainers_modules::postgres::Postgres;
     /// # use testcontainers_modules::rdbms::InitSql;
     /// let postgres_image = Postgres::default()
-    ///                                .with_init_sql(include_str!("path_to_init.sql"));
+    ///                                .with_init_sql(include_str!("path_to_init.sql").to_string().into_bytes());
     /// ```
-    fn with_init_sql(self, init_sql: impl ToString) -> Self;
+    fn with_init_sql(self, init_sql: impl Into<CopyDataSource>) -> Self;
 }
diff --git a/src/mariadb/mod.rs b/src/mariadb/mod.rs
index 455b499..eb7ffb2 100644
--- a/src/mariadb/mod.rs
+++ b/src/mariadb/mod.rs
@@ -1,6 +1,6 @@
 use std::borrow::Cow;
 
-use testcontainers::{core::WaitFor, CopyToContainer, Image};
+use testcontainers::{core::WaitFor, CopyDataSource, CopyToContainer, Image};
 
 const NAME: &str = "mariadb";
 const TAG: &str = "11.3";
@@ -27,7 +27,7 @@ const TAG: &str = "11.3";
 /// [`MariaDB docker image`]: https://hub.docker.com/_/mariadb
 #[derive(Debug, Default, Clone)]
 pub struct Mariadb {
-    init_sqls: Vec<CopyToContainer>,
+    copy_to_sources: Vec<CopyToContainer>,
 }
 
 impl Image for Mariadb {
@@ -55,17 +55,16 @@ impl Image for Mariadb {
         ]
     }
     fn copy_to_sources(&self) -> impl IntoIterator<Item = &CopyToContainer> {
-        &self.init_sqls
+        &self.copy_to_sources
     }
 }
 impl crate::InitSql for Mariadb {
-    fn with_init_sql(mut self, init_sql: impl ToString) -> Self {
-        let init_vec = init_sql.to_string().into_bytes();
+    fn with_init_sql(mut self, init_sql: impl Into<CopyDataSource>) -> Self {
         let target = format!(
             "/docker-entrypoint-initdb.d/init_{i}.sql",
-            i = self.init_sqls.len()
+            i = self.copy_to_sources.len()
         );
-        self.init_sqls.push(CopyToContainer::new(init_vec, target));
+        self.copy_to_sources.push(CopyToContainer::new(init_sql.into(), target));
         self
     }
 }
@@ -83,7 +82,7 @@ mod tests {
     fn mariadb_with_init_sql() -> Result<(), Box<dyn std::error::Error + 'static>> {
         use crate::InitSql;
         let node = MariadbImage::default()
-            .with_init_sql("CREATE TABLE foo (bar varchar(255));")
+            .with_init_sql("CREATE TABLE foo (bar varchar(255));".to_string().into_bytes())
             .start()?;
 
         let connection_string = &format!(
@@ -93,10 +92,10 @@ mod tests {
         );
         let mut conn = mysql::Conn::new(mysql::Opts::from_url(connection_string).unwrap()).unwrap();
 
-        let rows = conn.query("INSERT INTO foo(bar) VALUES ('blub')").unwrap();
+        let rows:Vec<String> = conn.query("INSERT INTO foo(bar) VALUES ('blub')").unwrap();
         assert_eq!(rows.len(), 0);
 
-        let rows = conn.query("SELECT bar FROM foo").unwrap();
+        let rows:Vec<String> = conn.query("SELECT bar FROM foo").unwrap();
         assert_eq!(rows.len(), 1);
         Ok(())
     }
diff --git a/src/mysql/mod.rs b/src/mysql/mod.rs
index e6e06ef..510c04a 100644
--- a/src/mysql/mod.rs
+++ b/src/mysql/mod.rs
@@ -1,6 +1,6 @@
 use std::borrow::Cow;
 
-use testcontainers::{core::WaitFor, CopyToContainer, Image};
+use testcontainers::{core::WaitFor, CopyDataSource, CopyToContainer, Image};
 
 const NAME: &str = "mysql";
 const TAG: &str = "8.1";
@@ -27,7 +27,7 @@ const TAG: &str = "8.1";
 /// [`MySQL docker image`]: https://hub.docker.com/_/mysql
 #[derive(Debug, Default, Clone)]
 pub struct Mysql {
-    init_sqls: Vec<CopyToContainer>,
+    copy_to_sources: Vec<CopyToContainer>,
 }
 
 impl Image for Mysql {
@@ -55,17 +55,16 @@ impl Image for Mysql {
         ]
     }
     fn copy_to_sources(&self) -> impl IntoIterator<Item = &CopyToContainer> {
-        &self.init_sqls
+        &self.copy_to_sources
     }
 }
 impl crate::InitSql for Mysql {
-    fn with_init_sql(mut self, init_sql: impl ToString) -> Self {
-        let init_vec = init_sql.to_string().into_bytes();
+    fn with_init_sql(mut self, init_sql: impl Into<CopyDataSource>) -> Self {
         let target = format!(
             "/docker-entrypoint-initdb.d/init_{i}.sql",
-            i = self.init_sqls.len()
+            i = self.copy_to_sources.len()
         );
-        self.init_sqls.push(CopyToContainer::new(init_vec, target));
+        self.copy_to_sources.push(CopyToContainer::new(init_sql.into(), target));
         self
     }
 }
@@ -84,7 +83,7 @@ mod tests {
     fn mysql_with_init_sql() -> Result<(), Box<dyn std::error::Error + 'static>> {
         use crate::InitSql;
         let node = crate::mysql::Mysql::default()
-            .with_init_sql("CREATE TABLE foo (bar varchar(255));")
+            .with_init_sql("CREATE TABLE foo (bar varchar(255));".to_string().into_bytes())
             .start()?;
 
         let connection_string = &format!(
@@ -94,10 +93,10 @@ mod tests {
         );
         let mut conn = mysql::Conn::new(mysql::Opts::from_url(connection_string).unwrap()).unwrap();
 
-        let rows = conn.query("INSERT INTO foo(bar) VALUES ('blub')").unwrap();
+        let rows:Vec<String> = conn.query("INSERT INTO foo(bar) VALUES ('blub')").unwrap();
         assert_eq!(rows.len(), 0);
 
-        let rows = conn.query("SELECT bar FROM foo").unwrap();
+        let rows:Vec<String> = conn.query("SELECT bar FROM foo").unwrap();
         assert_eq!(rows.len(), 1);
         Ok(())
     }
diff --git a/src/postgres/mod.rs b/src/postgres/mod.rs
index 3642cd1..9545d62 100644
--- a/src/postgres/mod.rs
+++ b/src/postgres/mod.rs
@@ -1,9 +1,6 @@
 use std::{borrow::Cow, collections::HashMap};
 
-use testcontainers::{
-    core::{Mount, WaitFor},
-    CopyToContainer, Image,
-};
+use testcontainers::{core::WaitFor, CopyDataSource, CopyToContainer, Image};
 
 const NAME: &str = "postgres";
 const TAG: &str = "11-alpine";
@@ -33,7 +30,7 @@ const TAG: &str = "11-alpine";
 #[derive(Debug, Clone)]
 pub struct Postgres {
     env_vars: HashMap<String, String>,
-    init_sqls: Vec<CopyToContainer>,
+    copy_to_sources: Vec<CopyToContainer>,
 }
 
 impl Postgres {
@@ -67,13 +64,12 @@ impl Postgres {
     }
 }
 impl crate::InitSql for Postgres {
-    fn with_init_sql(mut self, init_sql: impl ToString) -> Self {
-        let init_vec = init_sql.to_string().into_bytes();
+    fn with_init_sql(mut self, init_sql: impl Into<CopyDataSource>) -> Self {
         let target = format!(
             "/docker-entrypoint-initdb.d/init_{i}.sql",
-            i = self.init_sqls.len()
+            i = self.copy_to_sources.len()
         );
-        self.init_sqls.push(CopyToContainer::new(init_vec, target));
+        self.copy_to_sources.push(CopyToContainer::new(init_sql.into(), target));
         self
     }
 }
@@ -87,7 +83,7 @@ impl Default for Postgres {
 
         Self {
             env_vars,
-            init_sqls: Vec::new(),
+            copy_to_sources: Vec::new(),
         }
     }
 }
@@ -114,7 +110,7 @@ impl Image for Postgres {
         &self.env_vars
     }
     fn copy_to_sources(&self) -> impl IntoIterator<Item = &CopyToContainer> {
-        &self.init_sqls
+        &self.copy_to_sources
     }
 }
 
@@ -170,7 +166,7 @@ mod tests {
     fn postgres_with_init_sql() -> Result<(), Box<dyn std::error::Error + 'static>> {
         use crate::InitSql;
         let node = Postgres::default()
-            .with_init_sql("CREATE TABLE foo (bar varchar(255));")
+            .with_init_sql("CREATE TABLE foo (bar varchar(255));".to_string().into_bytes())
             .start()?;
 
         let connection_string = &format!(