diff --git a/src/rcore.rs b/src/rcore.rs
index 80dae13..d257a36 100644
--- a/src/rcore.rs
+++ b/src/rcore.rs
@@ -43,7 +43,7 @@ pub use self::resolution::{
     Address, HashResolution, HashResolutionResult, LookupError, Resolution, ResolutionError,
     ResolutionFailure, ResolutionResult, Resolver, ResolverMap,
 };
-pub use self::singular::SingularResolution;
+pub use self::singular::{SingularError, SingularResolution};
 pub use self::to_hex::hex;
 pub use self::topology::MentionableTop;
 
diff --git a/src/rcore/singular.rs b/src/rcore/singular.rs
index 81a44f0..4c6af2c 100644
--- a/src/rcore/singular.rs
+++ b/src/rcore/singular.rs
@@ -1,3 +1,5 @@
+use std::fmt::Display;
+
 use super::*;
 
 pub trait SingularResolution<'a, Ctx: Context<'a>>: 'a + Send + Sync {
@@ -17,3 +19,38 @@ impl<'a, Ctx: Context<'a>, A: Mentionable<'a, Ctx>> SingularResolution<'a, Ctx>
         self.point
     }
 }
+
+#[derive(Debug)]
+pub enum SingularError {
+    OutOfBounds {
+        index: usize,
+        len: usize,
+    },
+    Mismatch {
+        index: usize,
+        expected: Hash,
+        point: Hash,
+    },
+}
+
+impl Display for SingularError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::OutOfBounds { index, len } => {
+                write!(f, "singularity out-of-bounds: {index}/{len}")
+            }
+            Self::Mismatch {
+                index,
+                expected,
+                point,
+            } => write!(
+                f,
+                "address mismatch at index {index}: {}!={}",
+                hex(expected),
+                hex(point),
+            ),
+        }
+    }
+}
+
+impl Error for SingularError {}
diff --git a/src/rstd/singular.rs b/src/rstd/singular.rs
index 1c45c81..69a2a0c 100644
--- a/src/rstd/singular.rs
+++ b/src/rstd/singular.rs
@@ -25,41 +25,6 @@ struct SingularRobust<'a, Ctx: Context<'a>> {
     resolver: Arc<SingularResolver<'a, Ctx>>,
 }
 
-#[derive(Debug)]
-pub enum SingularError {
-    OutOfBounds {
-        index: usize,
-        len: usize,
-    },
-    Mismatch {
-        index: usize,
-        expected: Hash,
-        point: Hash,
-    },
-}
-
-impl Display for SingularError {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        match self {
-            Self::OutOfBounds { index, len } => {
-                write!(f, "singularity out-of-bounds: {index}/{len}")
-            }
-            Self::Mismatch {
-                index,
-                expected,
-                point,
-            } => write!(
-                f,
-                "address mismatch at index {index}: {}!={}",
-                hex(expected),
-                hex(point),
-            ),
-        }
-    }
-}
-
-impl Error for SingularError {}
-
 impl<'a, Ctx: Context<'a>> SingularResolver<'a, Ctx> {
     pub fn from_mentionable<A: Mentionable<'a, Ctx>>(a: &A) -> Self {
         let mut points = Vec::new();
diff --git a/src/testing.rs b/src/testing.rs
index 8659db8..4cd8aa0 100644
--- a/src/testing.rs
+++ b/src/testing.rs
@@ -7,7 +7,6 @@ use sha2::{Digest, Sha256};
 
 use crate::func::{context::*, *};
 use crate::rcore::*;
-use crate::rstd::singular::*;
 use crate::rstd::{inject::*, typeless::*};
 
 pub struct NoDiagnostic;