diff --git a/libosdp/src/pdinfo.rs b/libosdp/src/pdinfo.rs
index cb4ba29..9c7505c 100644
--- a/libosdp/src/pdinfo.rs
+++ b/libosdp/src/pdinfo.rs
@@ -250,12 +250,11 @@ impl PdInfoBuilder {
 impl PdInfo {
     /// Get a C-repr struct for PdInfo that LibOSDP can operate on.
     pub fn as_struct(&mut self) -> libosdp_sys::osdp_pd_info_t {
-        let scbk;
-        if let Some(key) = self.scbk.as_mut() {
-            scbk = key.as_mut_ptr();
+        let scbk = if let Some(key) = self.scbk {
+            Box::into_raw(Box::new(key)) as *mut _
         } else {
-            scbk = std::ptr::null_mut::<u8>();
-        }
+            std::ptr::null_mut::<u8>()
+        };
         libosdp_sys::osdp_pd_info_t {
             name: self.name.as_ptr(),
             baud_rate: self.baud_rate,