diff --git a/core-traits/lib.rs b/core-traits/lib.rs
index fd93c47e..2e32e8c5 100644
--- a/core-traits/lib.rs
+++ b/core-traits/lib.rs
@@ -73,6 +73,11 @@ use edn::entities::{
 };
 
 pub mod values;
+mod value_type_set;
+
+pub use value_type_set::{
+    ValueTypeSet,
+};
 
 /// Represents one entid in the entid space.
 ///
diff --git a/core/src/value_type_set.rs b/core-traits/value_type_set.rs
similarity index 99%
rename from core/src/value_type_set.rs
rename to core-traits/value_type_set.rs
index c194c57b..c510ad82 100644
--- a/core/src/value_type_set.rs
+++ b/core-traits/value_type_set.rs
@@ -8,11 +8,11 @@
 // CONDITIONS OF ANY KIND, either express or implied. See the License for the
 // specific language governing permissions and limitations under the License.
 
-use ::enum_set::{
+use enum_set::{
     EnumSet,
 };
 
-use core_traits::{
+use ::{
     ValueType,
 };
 
diff --git a/core/src/lib.rs b/core/src/lib.rs
index 183e6191..22acdfec 100644
--- a/core/src/lib.rs
+++ b/core/src/lib.rs
@@ -61,7 +61,6 @@ pub use cache::{
 /// Core types defining a Mentat knowledge base.
 mod types;
 mod tx_report;
-mod value_type_set;
 mod sql_types;
 
 pub use tx_report::{
@@ -72,10 +71,6 @@ pub use types::{
     ValueTypeTag,
 };
 
-pub use value_type_set::{
-    ValueTypeSet,
-};
-
 pub use sql_types::{
     SQLTypeAffinity,
     SQLValueType,
diff --git a/core/src/sql_types.rs b/core/src/sql_types.rs
index 1791df10..7f267b9b 100644
--- a/core/src/sql_types.rs
+++ b/core/src/sql_types.rs
@@ -14,16 +14,13 @@ use std::collections::{
 
 use core_traits::{
     ValueType,
+    ValueTypeSet,
 };
 
 use types::{
     ValueTypeTag,
 };
 
-use value_type_set::{
-    ValueTypeSet,
-};
-
 /// Type safe representation of the possible return values from SQLite's `typeof`
 #[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialOrd, PartialEq)]
 pub enum SQLTypeAffinity {
diff --git a/query-algebrizer/src/clauses/convert.rs b/query-algebrizer/src/clauses/convert.rs
index 67bdc1e9..006beb3d 100644
--- a/query-algebrizer/src/clauses/convert.rs
+++ b/query-algebrizer/src/clauses/convert.rs
@@ -10,6 +10,7 @@
 
 use core_traits::{
     ValueType,
+    ValueTypeSet,
     TypedValue,
 };
 
@@ -17,7 +18,6 @@ use mentat_core::{
     HasSchema,
     Schema,
     SQLValueType,
-    ValueTypeSet,
 };
 
 use edn::query::{
diff --git a/query-algebrizer/src/clauses/ground.rs b/query-algebrizer/src/clauses/ground.rs
index 28d78700..062e7d1c 100644
--- a/query-algebrizer/src/clauses/ground.rs
+++ b/query-algebrizer/src/clauses/ground.rs
@@ -10,12 +10,12 @@
 
 use core_traits::{
     ValueType,
+    ValueTypeSet,
     TypedValue,
 };
 
 use mentat_core::{
     Schema,
-    ValueTypeSet,
 };
 
 use edn::query::{
diff --git a/query-algebrizer/src/clauses/mod.rs b/query-algebrizer/src/clauses/mod.rs
index 8924e747..d860d6b7 100644
--- a/query-algebrizer/src/clauses/mod.rs
+++ b/query-algebrizer/src/clauses/mod.rs
@@ -29,6 +29,7 @@ use core_traits::{
     Entid,
     KnownEntid,
     ValueType,
+    ValueTypeSet,
     TypedValue,
 };
 
@@ -37,7 +38,6 @@ use mentat_core::{
     Cloned,
     HasSchema,
     Schema,
-    ValueTypeSet,
 };
 
 use mentat_core::counter::RcCounter;
diff --git a/query-algebrizer/src/clauses/not.rs b/query-algebrizer/src/clauses/not.rs
index 1a40650e..223ea194 100644
--- a/query-algebrizer/src/clauses/not.rs
+++ b/query-algebrizer/src/clauses/not.rs
@@ -93,12 +93,12 @@ mod testing {
     use core_traits::{
         TypedValue,
         ValueType,
+        ValueTypeSet,
     };
 
     use mentat_core::{
         Attribute,
         Schema,
-        ValueTypeSet,
     };
 
     use edn::query::{
diff --git a/query-algebrizer/src/clauses/or.rs b/query-algebrizer/src/clauses/or.rs
index a6883ea7..d84bab2d 100644
--- a/query-algebrizer/src/clauses/or.rs
+++ b/query-algebrizer/src/clauses/or.rs
@@ -14,7 +14,7 @@ use std::collections::{
     BTreeSet,
 };
 
-use mentat_core::{
+use core_traits::{
     ValueTypeSet,
 };
 
diff --git a/query-algebrizer/src/clauses/pattern.rs b/query-algebrizer/src/clauses/pattern.rs
index 9809a5c9..6716e7eb 100644
--- a/query-algebrizer/src/clauses/pattern.rs
+++ b/query-algebrizer/src/clauses/pattern.rs
@@ -12,12 +12,12 @@ use core_traits::{
     Entid,
     ValueType,
     TypedValue,
+    ValueTypeSet,
 };
 
 use mentat_core::{
     Cloned,
     HasSchema,
-    ValueTypeSet,
 };
 
 use edn::query::{
@@ -660,10 +660,12 @@ mod testing {
     use std::collections::BTreeSet;
 
     use mentat_core::attribute::Unique;
+    use core_traits::{
+        ValueTypeSet,
+    };
     use mentat_core::{
         Attribute,
         Schema,
-        ValueTypeSet,
     };
 
     use edn::query::{
diff --git a/query-algebrizer/src/clauses/predicate.rs b/query-algebrizer/src/clauses/predicate.rs
index 5d1a7190..6628959d 100644
--- a/query-algebrizer/src/clauses/predicate.rs
+++ b/query-algebrizer/src/clauses/predicate.rs
@@ -10,11 +10,11 @@
 
 use core_traits::{
     ValueType,
+    ValueTypeSet,
 };
 
 use mentat_core::{
     Schema,
-    ValueTypeSet,
 };
 
 use edn::query::{
diff --git a/query-algebrizer/src/errors.rs b/query-algebrizer/src/errors.rs
index e2cc4143..4e1db709 100644
--- a/query-algebrizer/src/errors.rs
+++ b/query-algebrizer/src/errors.rs
@@ -12,9 +12,6 @@ use std; // To refer to std::result::Result.
 
 use core_traits::{
     ValueType,
-};
-
-use mentat_core::{
     ValueTypeSet,
 };
 
diff --git a/query-algebrizer/src/types.rs b/query-algebrizer/src/types.rs
index 5a981b9a..80292da6 100644
--- a/query-algebrizer/src/types.rs
+++ b/query-algebrizer/src/types.rs
@@ -18,11 +18,11 @@ use core_traits::{
     Entid,
     TypedValue,
     ValueType,
+    ValueTypeSet,
 };
 
 use mentat_core::{
     ValueRc,
-    ValueTypeSet,
 };
 
 use edn::query::{
diff --git a/query-algebrizer/tests/predicate.rs b/query-algebrizer/tests/predicate.rs
index 65081d5e..73bc8a0a 100644
--- a/query-algebrizer/tests/predicate.rs
+++ b/query-algebrizer/tests/predicate.rs
@@ -18,6 +18,7 @@ mod utils;
 use core_traits::{
     ValueType,
     TypedValue,
+    ValueTypeSet,
 };
 
 use mentat_core::{
@@ -25,7 +26,6 @@ use mentat_core::{
     DateTime,
     Schema,
     Utc,
-    ValueTypeSet,
 };
 
 use edn::query::{
diff --git a/query-projector/src/aggregates.rs b/query-projector/src/aggregates.rs
index bb4ec590..230dd150 100644
--- a/query-projector/src/aggregates.rs
+++ b/query-projector/src/aggregates.rs
@@ -10,9 +10,6 @@
 
 use core_traits::{
     ValueType,
-};
-
-use mentat_core::{
     ValueTypeSet,
 };
 
diff --git a/query-projector/src/errors.rs b/query-projector/src/errors.rs
index b9b37808..8dd38516 100644
--- a/query-projector/src/errors.rs
+++ b/query-projector/src/errors.rs
@@ -12,7 +12,7 @@ use std; // To refer to std::result::Result.
 
 use rusqlite;
 
-use mentat_core::{
+use core_traits::{
     ValueTypeSet,
 };
 use db_traits::errors::DbError;
diff --git a/query-projector/src/project.rs b/query-projector/src/project.rs
index dd1ee063..16bb8da4 100644
--- a/query-projector/src/project.rs
+++ b/query-projector/src/project.rs
@@ -16,10 +16,13 @@ use indexmap::{
     IndexSet,
 };
 
+use core_traits::{
+    ValueTypeSet,
+};
+
 use mentat_core::{
     SQLValueType,
     SQLValueTypeSet,
-    ValueTypeSet,
 };
 
 use mentat_core::util::{
diff --git a/query-translator/src/translate.rs b/query-translator/src/translate.rs
index bf7ff690..05daa80c 100644
--- a/query-translator/src/translate.rs
+++ b/query-translator/src/translate.rs
@@ -11,6 +11,7 @@
 use core_traits::{
     TypedValue,
     ValueType,
+    ValueTypeSet,
 };
 
 use mentat_core::{
@@ -19,7 +20,6 @@ use mentat_core::{
     SQLValueType,
     SQLValueTypeSet,
     ValueTypeTag,
-    ValueTypeSet,
 };
 
 use mentat_core::util::{
diff --git a/tests/query.rs b/tests/query.rs
index da45b53d..99166776 100644
--- a/tests/query.rs
+++ b/tests/query.rs
@@ -30,6 +30,7 @@ use core_traits::{
     Entid,
     KnownEntid,
     ValueType,
+    ValueTypeSet,
 };
 
 use mentat_core::{
@@ -37,7 +38,6 @@ use mentat_core::{
     HasSchema,
     Utc,
     Uuid,
-    ValueTypeSet,
 };
 
 use mentat_query_projector::{