diff --git a/src/client.rs b/src/client.rs
index cbe2929180..e89dc4f053 100644
--- a/src/client.rs
+++ b/src/client.rs
@@ -245,7 +245,7 @@ impl JanetClient {
     /// # }
     /// ```
     #[inline]
-    pub fn add_c_fn(&mut self, cfun_opt: CFunOptions) {
+    pub fn add_c_fn(&mut self, cfun_opt: CFunOptions<'static>) {
         if self.env().is_none() {
             self.env_table = Some(JanetEnvironment::default());
         }
diff --git a/src/env.rs b/src/env.rs
index 30dfeab9fd..b5e30fd79d 100644
--- a/src/env.rs
+++ b/src/env.rs
@@ -90,7 +90,7 @@ impl JanetEnvironment {
     /// Add a C function in the environment and register it on the VM.
     #[crate::cjvg("1.0.0", "1.17.0")]
     #[inline]
-    pub fn add_c_fn(&mut self, cfun_opt: CFunOptions) {
+    pub fn add_c_fn(&mut self, cfun_opt: CFunOptions<'static>) {
         let namespace = cfun_opt
             .namespace
             .map(|s| s.as_ptr())
@@ -121,7 +121,7 @@ impl JanetEnvironment {
     /// Add a C function in the environment and register it on the VM.
     #[crate::cjvg("1.17.0")]
     #[inline]
-    pub fn add_c_fn(&mut self, cfun_opt: CFunOptions) {
+    pub fn add_c_fn(&mut self, cfun_opt: CFunOptions<'static>) {
         let namespace = cfun_opt
             .namespace
             .map(|s| s.as_ptr())