diff --git a/query-algebrizer/src/cc.rs b/query-algebrizer/src/cc.rs
index f09ecf4e..73c6cfcc 100644
--- a/query-algebrizer/src/cc.rs
+++ b/query-algebrizer/src/cc.rs
@@ -53,6 +53,7 @@ use types::{
     ColumnConstraint,
     DatomsColumn,
     DatomsTable,
+    EmptyBecause,
     NumericComparison,
     QualifiedAlias,
     QueryValue,
@@ -160,19 +161,6 @@ pub struct ConjoiningClauses {
     extracted_types: BTreeMap<Variable, QualifiedAlias>,
 }
 
-#[derive(PartialEq)]
-pub enum EmptyBecause {
-    // Var, existing, desired.
-    TypeMismatch(Variable, HashSet<ValueType>, ValueType),
-    NonNumericArgument,
-    UnresolvedIdent(NamespacedKeyword),
-    InvalidAttributeIdent(NamespacedKeyword),
-    InvalidAttributeEntid(Entid),
-    InvalidBinding(DatomsColumn, TypedValue),
-    ValueTypeMismatch(ValueType, TypedValue),
-    AttributeLookupFailed,         // Catch-all, because the table lookup code is lazy. TODO
-}
-
 impl Debug for EmptyBecause {
     fn fmt(&self, f: &mut Formatter) -> ::std::fmt::Result {
         use self::EmptyBecause::*;
diff --git a/query-algebrizer/src/types.rs b/query-algebrizer/src/types.rs
index a726a3c7..274c1cac 100644
--- a/query-algebrizer/src/types.rs
+++ b/query-algebrizer/src/types.rs
@@ -8,6 +8,8 @@
 // CONDITIONS OF ANY KIND, either express or implied. See the License for the
 // specific language governing permissions and limitations under the License.
 
+use std::collections::HashSet;
+
 use std::fmt::{
     Debug,
     Formatter,
@@ -19,6 +21,12 @@ use mentat_core::{
     TypedValue,
     ValueType,
 };
+
+use mentat_query::{
+    NamespacedKeyword,
+    Variable,
+};
+
 /// This enum models the fixed set of default tables we have -- two
 /// tables and two views.
 #[derive(PartialEq, Eq, Clone, Copy, Debug)]
@@ -204,3 +212,16 @@ impl Debug for ColumnConstraint {
         }
     }
 }
+
+#[derive(PartialEq)]
+pub enum EmptyBecause {
+    // Var, existing, desired.
+    TypeMismatch(Variable, HashSet<ValueType>, ValueType),
+    NonNumericArgument,
+    UnresolvedIdent(NamespacedKeyword),
+    InvalidAttributeIdent(NamespacedKeyword),
+    InvalidAttributeEntid(Entid),
+    InvalidBinding(DatomsColumn, TypedValue),
+    ValueTypeMismatch(ValueType, TypedValue),
+    AttributeLookupFailed,         // Catch-all, because the table lookup code is lazy. TODO
+}
\ No newline at end of file