diff --git a/lib/wasi/src/runners/mod.rs b/lib/wasi/src/runners/mod.rs
index ae12493aab6..3aca293256e 100644
--- a/lib/wasi/src/runners/mod.rs
+++ b/lib/wasi/src/runners/mod.rs
@@ -14,7 +14,7 @@ pub use self::runner::Runner;
 use anyhow::Error;
 use wasmer::{Engine, Module};
 
-pub type CompileModule = dyn Fn(&Engine, &[u8]) -> Result<Module, Error>;
+pub type CompileModule = dyn Fn(&Engine, &[u8]) -> Result<Module, Error> + Send + Sync;
 
 #[derive(Debug, Clone, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
 pub struct MappedDirectory {
diff --git a/lib/wasi/src/runners/wasi.rs b/lib/wasi/src/runners/wasi.rs
index 59f65231bf9..0c4d08f70d4 100644
--- a/lib/wasi/src/runners/wasi.rs
+++ b/lib/wasi/src/runners/wasi.rs
@@ -41,7 +41,7 @@ impl WasiRunner {
     /// Sets the compile function
     pub fn with_compile(
         mut self,
-        compile: impl Fn(&Engine, &[u8]) -> Result<Module, Error> + 'static,
+        compile: impl Fn(&Engine, &[u8]) -> Result<Module, Error> + Send + Sync + 'static,
     ) -> Self {
         self.compile = Some(Box::new(compile));
         self
@@ -190,3 +190,17 @@ impl crate::runners::Runner for WasiRunner {
         Ok(())
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn send_and_sync() {
+        fn assert_send<T: Send>() {}
+        fn assert_sync<T: Sync>() {}
+
+        assert_send::<WasiRunner>();
+        assert_sync::<WasiRunner>();
+    }
+}
diff --git a/lib/wasi/src/runners/wcgi/runner.rs b/lib/wasi/src/runners/wcgi/runner.rs
index beb3a25b9b6..b75c733946b 100644
--- a/lib/wasi/src/runners/wcgi/runner.rs
+++ b/lib/wasi/src/runners/wcgi/runner.rs
@@ -120,7 +120,7 @@ impl WcgiRunner {
     /// Sets the compile function
     pub fn with_compile(
         mut self,
-        compile: impl Fn(&Engine, &[u8]) -> Result<Module, Error> + 'static,
+        compile: impl Fn(&Engine, &[u8]) -> Result<Module, Error> + Send + Sync + 'static,
     ) -> Self {
         self.compile = Some(Arc::new(compile));
         self
@@ -374,3 +374,17 @@ pub trait Callbacks: Send + Sync + 'static {
 struct NoopCallbacks;
 
 impl Callbacks for NoopCallbacks {}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn send_and_sync() {
+        fn assert_send<T: Send>() {}
+        fn assert_sync<T: Sync>() {}
+
+        assert_send::<WcgiRunner>();
+        assert_sync::<WcgiRunner>();
+    }
+}