diff --git a/src/gucs/embedding.rs b/src/gucs/embedding.rs
index 895425596..bdb600f38 100644
--- a/src/gucs/embedding.rs
+++ b/src/gucs/embedding.rs
@@ -1,11 +1,23 @@
-use super::guc_string_parse;
 use embedding::OpenAIOptions;
 use pgrx::guc::{GucContext, GucFlags, GucRegistry, GucSetting};
 use std::ffi::CStr;
 
 pub fn openai_options() -> OpenAIOptions {
-    let base_url = guc_string_parse(&OPENAI_BASE_URL, "vectors.openai_base_url");
-    let api_key = guc_string_parse(&OPENAI_API_KEY, "vectors.openai_api_key");
+    use crate::error::*;
+    use pgrx::guc::GucSetting;
+    use std::ffi::CStr;
+    fn parse(target: &'static GucSetting<Option<&'static CStr>>, name: &'static str) -> String {
+        let value = match target.get() {
+            Some(s) => s,
+            None => bad_guc_literal(name, "should not be `NULL`"),
+        };
+        match value.to_str() {
+            Ok(s) => s.to_string(),
+            Err(_e) => bad_guc_literal(name, "should be a valid UTF-8 string"),
+        }
+    }
+    let base_url = parse(&OPENAI_BASE_URL, "vectors.openai_base_url");
+    let api_key = parse(&OPENAI_API_KEY, "vectors.openai_api_key");
     OpenAIOptions { base_url, api_key }
 }
 
diff --git a/src/gucs/mod.rs b/src/gucs/mod.rs
index a3dc64cf6..f43bed5b9 100644
--- a/src/gucs/mod.rs
+++ b/src/gucs/mod.rs
@@ -1,7 +1,3 @@
-use crate::error::*;
-use pgrx::guc::GucSetting;
-use std::ffi::CStr;
-
 pub mod embedding;
 pub mod executing;
 pub mod internal;
@@ -13,19 +9,9 @@ pub unsafe fn init() {
         internal::init();
         executing::init();
         embedding::init();
-    }
-}
-
-fn guc_string_parse(
-    target: &'static GucSetting<Option<&'static CStr>>,
-    name: &'static str,
-) -> String {
-    let value = match target.get() {
-        Some(s) => s,
-        None => bad_guc_literal(name, "should not be `NULL`"),
-    };
-    match value.to_str() {
-        Ok(s) => s.to_string(),
-        Err(_e) => bad_guc_literal(name, "should be a valid UTF-8 string"),
+        #[cfg(feature = "pg14")]
+        pgrx::pg_sys::EmitWarningsOnPlaceholders(c"vectors".as_ptr());
+        #[cfg(any(feature = "pg15", feature = "pg16", feature = "pg17"))]
+        pgrx::pg_sys::MarkGUCPrefixReserved(c"vectors".as_ptr());
     }
 }