diff --git a/keystore2/src/apc.rs b/keystore2/src/apc.rs
index 0096686..7d56dc9 100644
--- a/keystore2/src/apc.rs
+++ b/keystore2/src/apc.rs
@@ -21,6 +21,7 @@
     sync::{mpsc::Sender, Arc, Mutex},
 };
 
+use crate::error::anyhow_error_to_cstring;
 use crate::utils::{compat_2_response_code, ui_opts_2_compat, watchdog as wd};
 use android_security_apc::aidl::android::security::apc::{
     IConfirmationCallback::IConfirmationCallback,
@@ -110,7 +111,10 @@
                     _ => ResponseCode::SYSTEM_ERROR.0,
                 },
             };
-            Err(BinderStatus::new_service_specific_error(rc, None))
+            Err(BinderStatus::new_service_specific_error(
+                rc,
+                anyhow_error_to_cstring(&e).as_deref(),
+            ))
         },
         handle_ok,
     )
diff --git a/keystore2/src/authorization.rs b/keystore2/src/authorization.rs
index 04626bc..0c41507 100644
--- a/keystore2/src/authorization.rs
+++ b/keystore2/src/authorization.rs
@@ -15,6 +15,7 @@
 //! This module implements IKeystoreAuthorization AIDL interface.
 
 use crate::error::Error as KeystoreError;
+use crate::error::anyhow_error_to_cstring;
 use crate::globals::{ENFORCEMENTS, SUPER_KEY, DB, LEGACY_MIGRATOR};
 use crate::permission::KeystorePerm;
 use crate::super_key::UserState;
@@ -88,7 +89,10 @@
                     // as well.
                     _ => ResponseCode::SYSTEM_ERROR.0,
                 };
-                return Err(BinderStatus::new_service_specific_error(rc, None));
+                return Err(BinderStatus::new_service_specific_error(
+                    rc,
+                    anyhow_error_to_cstring(&e).as_deref(),
+                ));
             }
             let rc = match root_cause.downcast_ref::<Error>() {
                 Some(Error::Rc(rcode)) => rcode.0,
@@ -98,7 +102,10 @@
                     _ => ResponseCode::SYSTEM_ERROR.0,
                 },
             };
-            Err(BinderStatus::new_service_specific_error(rc, None))
+            Err(BinderStatus::new_service_specific_error(
+                rc,
+                anyhow_error_to_cstring(&e).as_deref(),
+            ))
         },
         handle_ok,
     )
diff --git a/keystore2/src/error.rs b/keystore2/src/error.rs
index f969cb6..42dd3d2 100644
--- a/keystore2/src/error.rs
+++ b/keystore2/src/error.rs
@@ -37,6 +37,7 @@
 };
 use keystore2_selinux as selinux;
 use std::cmp::PartialEq;
+use std::ffi::CString;
 
 /// This is the main Keystore error type. It wraps the Keystore `ResponseCode` generated
 /// from AIDL in the `Rc` variant and Keymint `ErrorCode` in the Km variant.
@@ -184,6 +185,20 @@
     )
 }
 
+/// This function turns an anyhow error into an optional CString.
+/// This is especially useful to add a message string to a service specific error.
+/// If the formatted string was not convertible because it contained a nul byte,
+/// None is returned and a warning is logged.
+pub fn anyhow_error_to_cstring(e: &anyhow::Error) -> Option<CString> {
+    match CString::new(format!("{:?}", e)) {
+        Ok(msg) => Some(msg),
+        Err(_) => {
+            log::warn!("Cannot convert error message to CStr. It contained a nul byte.");
+            None
+        }
+    }
+}
+
 /// This function behaves similar to map_or_log_error, but it does not log the errors, instead
 /// it calls map_err on the error before mapping it to a binder result allowing callers to
 /// log or transform the error before mapping it.
@@ -200,7 +215,10 @@
         |e| {
             let e = map_err(e);
             let rc = get_error_code(&e);
-            Err(BinderStatus::new_service_specific_error(rc, None))
+            Err(BinderStatus::new_service_specific_error(
+                rc,
+                anyhow_error_to_cstring(&e).as_deref(),
+            ))
         },
         handle_ok,
     )