diff --git a/crates/types/src/string.rs b/crates/types/src/string.rs
index fdda3768..95b78b20 100644
--- a/crates/types/src/string.rs
+++ b/crates/types/src/string.rs
@@ -138,11 +138,9 @@ impl Clone for String {
 
 impl Drop for String {
     fn drop(&mut self) {
-        // There's no way to know if the pointer we get from Neovim
-        // points to some `malloc`ed memory or to a static/borrowed string.
-        //
-        // TODO: we're leaking memory here if the pointer points to allocated
-        // memory.
+        if !self.as_ptr().is_null() {
+            unsafe { libc::free(self.as_ptr() as *mut ffi::c_void) }
+        }
     }
 }
 
diff --git a/crates/types/src/string_builder.rs b/crates/types/src/string_builder.rs
index 965a1abf..d5ba5b9d 100644
--- a/crates/types/src/string_builder.rs
+++ b/crates/types/src/string_builder.rs
@@ -210,14 +210,6 @@ impl fmt::Write for StringBuilder {
     }
 }
 
-impl Drop for StringBuilder {
-    fn drop(&mut self) {
-        if !self.inner.as_ptr().is_null() {
-            unsafe { libc::free(self.inner.as_ptr() as *mut ffi::c_void) }
-        }
-    }
-}
-
 #[cold]
 #[inline(never)]
 fn unable_to_alloc_memory() {