diff --git a/query/Cargo.toml b/query/Cargo.toml
index e2b7baa7..c074054a 100644
--- a/query/Cargo.toml
+++ b/query/Cargo.toml
@@ -6,3 +6,6 @@ version = "0.0.1"
 
 [dependencies.edn]
   path = "../edn"
+
+[dependencies.mentat_core]
+  path = "../core"
diff --git a/query/src/lib.rs b/query/src/lib.rs
index be81992c..000122a6 100644
--- a/query/src/lib.rs
+++ b/query/src/lib.rs
@@ -31,9 +31,11 @@
 ///! a tradeoff against well-typed function signatures and other such boundaries.
 
 extern crate edn;
+extern crate mentat_core;
 
 use edn::{BigInt, OrderedFloat};
 pub use edn::{NamespacedKeyword, PlainSymbol};
+use mentat_core::TypedValue;
 
 pub type SrcVarName = String;          // Do not include the required syntactic '$'.
 
@@ -101,6 +103,17 @@ pub enum NonIntegerConstant {
     Text(String),
 }
 
+impl NonIntegerConstant {
+    pub fn into_typed_value(self) -> TypedValue {
+        match self {
+            NonIntegerConstant::BigInteger(_) => unimplemented!(),     // TODO: #280.
+            NonIntegerConstant::Boolean(v) => TypedValue::Boolean(v),
+            NonIntegerConstant::Float(v) => TypedValue::Double(v),
+            NonIntegerConstant::Text(v) => TypedValue::String(v),
+        }
+    }
+}
+
 pub enum FnArg {
     Variable(Variable),
     SrcVar(SrcVar),