diff --git a/src/bin/cache_check.rs b/src/bin/cache_check.rs
index 4db7e9b..f266161 100644
--- a/src/bin/cache_check.rs
+++ b/src/bin/cache_check.rs
@@ -14,6 +14,12 @@ use thinp::report::*;
 fn main() {
     let parser = App::new("cache_check")
         .version(thinp::version::tools_version())
+        .arg(
+            Arg::with_name("ASYNC_IO")
+                .help("Force use of io_uring for synchronous io")
+                .long("async-io")
+                .hidden(true),
+        )
         .arg(
             Arg::with_name("INPUT")
                 .help("Specify the input device to check")
@@ -75,7 +81,7 @@ fn main() {
 
     let opts = CacheCheckOptions {
         dev: &input_file,
-        async_io: false,
+        async_io: matches.is_present("ASYNC_IO"),
         sb_only: matches.is_present("SB_ONLY"),
         skip_mappings: matches.is_present("SKIP_MAPPINGS"),
         skip_hints: matches.is_present("SKIP_HINTS"),
diff --git a/src/bin/cache_dump.rs b/src/bin/cache_dump.rs
index e706f0b..be6ceca 100644
--- a/src/bin/cache_dump.rs
+++ b/src/bin/cache_dump.rs
@@ -11,6 +11,12 @@ fn main() {
     let parser = App::new("cache_dump")
         .version(thinp::version::tools_version())
         .about("Dump the cache metadata to stdout in XML format")
+        .arg(
+            Arg::with_name("ASYNC_IO")
+                .help("Force use of io_uring for synchronous io")
+                .long("async-io")
+                .hidden(true),
+        )
         .arg(
             Arg::with_name("REPAIR")
                 .help("Repair the metadata whilst dumping it")
@@ -42,7 +48,7 @@ fn main() {
     let opts = CacheDumpOptions {
         input: input_file,
         output: output_file,
-        async_io: false,
+        async_io: matches.is_present("ASYNC_IO"),
         repair: matches.is_present("REPAIR"),
     };
 
diff --git a/src/bin/cache_restore.rs b/src/bin/cache_restore.rs
index 9375c91..d5eda5e 100644
--- a/src/bin/cache_restore.rs
+++ b/src/bin/cache_restore.rs
@@ -15,6 +15,12 @@ fn main() {
     let parser = App::new("cache_restore")
         .version(thinp::version::tools_version())
         .about("Convert XML format metadata to binary.")
+        .arg(
+            Arg::with_name("ASYNC_IO")
+                .help("Force use of io_uring for synchronous io")
+                .long("async-io")
+                .hidden(true),
+        )
         .arg(
             Arg::with_name("OVERRIDE_MAPPING_ROOT")
                 .help("Specify a mapping root to use")
@@ -37,11 +43,6 @@ fn main() {
                 .long("output")
                 .value_name("OUTPUT")
                 .required(true),
-        )
-        .arg(
-            Arg::with_name("SYNC_IO")
-                .help("Force use of synchronous io")
-                .long("sync-io"),
         );
 
     let matches = parser.get_matches();
@@ -66,7 +67,7 @@ fn main() {
     let opts = CacheRestoreOptions {
         input: &input_file,
         output: &output_file,
-        async_io: !matches.is_present("SYNC_IO"),
+        async_io: matches.is_present("ASYNC_IO"),
         report,
     };
 
diff --git a/src/bin/thin_check.rs b/src/bin/thin_check.rs
index 2298ce9..c3ab573 100644
--- a/src/bin/thin_check.rs
+++ b/src/bin/thin_check.rs
@@ -16,6 +16,12 @@ fn main() {
     let parser = App::new("thin_check")
         .version(thinp::version::tools_version())
         .about("Validates thin provisioning metadata on a device or file.")
+        .arg(
+            Arg::with_name("ASYNC_IO")
+                .help("Force use of io_uring for synchronous io")
+                .long("async-io")
+                .hidden(true),
+        )
         .arg(
             Arg::with_name("QUIET")
                 .help("Suppress output messages, return only exit code.")
@@ -66,16 +72,6 @@ fn main() {
                 .help("Specify the input device to check")
                 .required(true)
                 .index(1),
-        )
-        .arg(
-            Arg::with_name("ASYNC_IO")
-                .help("Force use of io_uring for asynchronous IO")
-                .long("async-io"),
-        )
-        .arg(
-            Arg::with_name("SYNC_IO")
-                .help("Force use of synchronous IO (currently the default)")
-                .long("sync-io"),
         );
 
     let matches = parser.get_matches();
@@ -96,11 +92,6 @@ fn main() {
         report = Arc::new(mk_simple_report());
     }
 
-    if matches.is_present("SYNC_IO") && matches.is_present("ASYNC_IO") {
-        eprintln!("--sync-io and --async-io may not be used at the same time.");
-        process::exit(1);
-    }
-
     let engine: Arc<dyn IoEngine + Send + Sync>;
 
     if matches.is_present("ASYNC_IO") {
diff --git a/src/bin/thin_dump.rs b/src/bin/thin_dump.rs
index b9f08d0..af238dd 100644
--- a/src/bin/thin_dump.rs
+++ b/src/bin/thin_dump.rs
@@ -15,6 +15,12 @@ fn main() {
     let parser = App::new("thin_dump")
         .version(thinp::version::tools_version())
         .about("Dump thin-provisioning metadata to stdout in XML format")
+        .arg(
+            Arg::with_name("ASYNC_IO")
+                .help("Force use of io_uring for synchronous io")
+                .long("async-io")
+                .hidden(true),
+        )
         .arg(
             Arg::with_name("QUIET")
                 .help("Suppress output messages, return only exit code.")
@@ -32,11 +38,6 @@ fn main() {
                 .help("Do not dump the mappings")
                 .long("skip-mappings"),
         )
-        .arg(
-            Arg::with_name("SYNC_IO")
-                .help("Force use of synchronous io")
-                .long("sync-io"),
-        )
         .arg(
             Arg::with_name("METADATA_SNAPSHOT")
                 .help("Access the metadata snapshot on a live pool")
@@ -84,7 +85,7 @@ fn main() {
     let opts = ThinDumpOptions {
         input: input_file,
         output: output_file,
-        async_io: !matches.is_present("SYNC_IO"),
+        async_io: matches.is_present("ASYNC_IO"),
         report,
     };
 
diff --git a/src/bin/thin_restore.rs b/src/bin/thin_restore.rs
index 243f3a4..8654613 100644
--- a/src/bin/thin_restore.rs
+++ b/src/bin/thin_restore.rs
@@ -15,6 +15,12 @@ fn main() {
     let parser = App::new("thin_restore")
         .version(thinp::version::tools_version())
         .about("Convert XML format metadata to binary.")
+        .arg(
+            Arg::with_name("ASYNC_IO")
+                .help("Force use of io_uring for synchronous io")
+                .long("async-io")
+                .hidden(true),
+        )
         .arg(
             Arg::with_name("OVERRIDE_MAPPING_ROOT")
                 .help("Specify a mapping root to use")
@@ -37,11 +43,6 @@ fn main() {
                 .long("output")
                 .value_name("OUTPUT")
                 .required(true),
-        )
-        .arg(
-            Arg::with_name("SYNC_IO")
-                .help("Force use of synchronous io")
-                .long("sync-io"),
         );
 
     let matches = parser.get_matches();
@@ -66,7 +67,7 @@ fn main() {
     let opts = ThinRestoreOptions {
         input: &input_file,
         output: &output_file,
-        async_io: !matches.is_present("SYNC_IO"),
+        async_io: matches.is_present("ASYNC_IO"),
         report,
     };