diff --git a/Cargo.lock b/Cargo.lock
index 8b10ef885..500a8ce3a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1271,6 +1271,7 @@ dependencies = [
  "limbo_ext",
  "limbo_macros",
  "limbo_percentile",
+ "limbo_regexp",
  "limbo_uuid",
  "log",
  "miette",
diff --git a/core/Cargo.toml b/core/Cargo.toml
index 81f3b454c..694617ec3 100644
--- a/core/Cargo.toml
+++ b/core/Cargo.toml
@@ -14,7 +14,7 @@ name = "limbo_core"
 path = "lib.rs"
 
 [features]
-default = ["fs", "json", "uuid", "io_uring", "percentile"]
+default = ["fs", "json", "uuid", "io_uring"]
 fs = []
 json = [
     "dep:jsonb",
@@ -24,6 +24,7 @@ json = [
 uuid = ["limbo_uuid/static"]
 io_uring = ["dep:io-uring", "rustix/io_uring"]
 percentile = ["limbo_percentile/static"]
+regexp = ["limbo_regexp/static"]
 
 [target.'cfg(target_os = "linux")'.dependencies]
 io-uring = { version = "0.6.1", optional = true }
@@ -60,6 +61,7 @@ rand = "0.8.5"
 bumpalo = { version = "3.16.0", features = ["collections", "boxed"] }
 limbo_macros = { path = "../macros" }
 limbo_uuid = { path = "../extensions/uuid", optional = true, features = ["static"] }
+limbo_regexp = { path = "../extensions/regexp", optional = true, features = ["static"] }
 limbo_percentile = { path = "../extensions/percentile", optional = true, features = ["static"] }
 miette = "7.4.0"
 
diff --git a/core/ext/mod.rs b/core/ext/mod.rs
index 377853769..cbd2fa258 100644
--- a/core/ext/mod.rs
+++ b/core/ext/mod.rs
@@ -75,28 +75,19 @@ impl Database {
     }
 
     pub fn register_builtins(&self) -> Result<(), String> {
+        let ext_api = self.build_limbo_ext();
         #[cfg(feature = "uuid")]
-        self.register_uuid()?;
-        #[cfg(feature = "percentile")]
-        self.register_percentile()?;
-        Ok(())
-    }
-
-    #[cfg(feature = "uuid")]
-    pub fn register_uuid(&self) -> Result<(), String> {
-        let ext_api = Box::new(self.build_limbo_ext());
         if unsafe { !limbo_uuid::register_extension_static(&ext_api).is_ok() } {
             return Err("Failed to register uuid extension".to_string());
         }
-        Ok(())
-    }
-
-    #[cfg(feature = "percentile")]
-    pub fn register_percentile(&self) -> Result<(), String> {
-        let ext_api = self.build_limbo_ext();
+        #[cfg(feature = "percentile")]
         if unsafe { !limbo_percentile::register_extension_static(&ext_api).is_ok() } {
             return Err("Failed to register percentile extension".to_string());
         }
+        #[cfg(feature = "regexp")]
+        if unsafe { !limbo_regexp::register_extension_static(&ext_api).is_ok() } {
+            return Err("Failed to register regexp extension".to_string());
+        }
         Ok(())
     }
 }
diff --git a/extensions/regexp/Cargo.toml b/extensions/regexp/Cargo.toml
index dc2f87c3b..9ca5c222f 100644
--- a/extensions/regexp/Cargo.toml
+++ b/extensions/regexp/Cargo.toml
@@ -6,11 +6,14 @@ edition.workspace = true
 license.workspace = true
 repository.workspace = true
 
+[features]
+static = ["limbo_ext/static"]
+
 [lib]
 crate-type = ["cdylib", "lib"]
 
 
 [dependencies]
-limbo_ext = { path = "../core"}
+limbo_ext = { path = "../core", features = ["static"] }
 regex = "1.11.1"
 log = "0.4.20"
diff --git a/testing/extensions.py b/testing/extensions.py
index 915465e9b..74755a012 100755
--- a/testing/extensions.py
+++ b/testing/extensions.py
@@ -133,7 +133,6 @@ def assert_specific_time(result):
 
 def test_uuid(pipe):
     specific_time = "01945ca0-3189-76c0-9a8f-caf310fc8b8e"
-
     # these are built into the binary, so we just test they work
     run_test(
         pipe,
@@ -210,7 +209,20 @@ def validate_percentile_disc(res):
 
 
 def test_aggregates(pipe):
-    # also built-in
+    extension_path = "./target/debug/liblimbo_percentile.so"
+    # assert no function before extension loads
+    run_test(
+        pipe,
+        "SELECT median(1);",
+        returns_error,
+        "median agg function returns null when ext not loaded",
+    )
+    run_test(
+        pipe,
+        f".load {extension_path}",
+        returns_null,
+        "load extension command works properly",
+    )
     run_test(
         pipe,
         "select median(value) from numbers;",
@@ -260,4 +272,3 @@ def main():
 
 if __name__ == "__main__":
     main()
-