diff --git a/src/extension/prelude.rs b/src/extension/prelude.rs
index a79497a61..15a20930e 100644
--- a/src/extension/prelude.rs
+++ b/src/extension/prelude.rs
@@ -60,9 +60,12 @@ pub(crate) const QB_CUSTOM_T: CustomType = CustomType::new_simple(
     TypeBound::Any,
 );
 
-pub(crate) const QB_T: Type = Type::new_extension(QB_CUSTOM_T);
-pub(crate) const USIZE_T: Type = Type::new_extension(USIZE_CUSTOM_T);
-pub(crate) const BOOL_T: Type = Type::new_simple_predicate(2);
+/// Qubit type.
+pub const QB_T: Type = Type::new_extension(QB_CUSTOM_T);
+/// Unsigned size type.
+pub const USIZE_T: Type = Type::new_extension(USIZE_CUSTOM_T);
+/// Boolean type - Sum of two units.
+pub const BOOL_T: Type = Type::new_simple_predicate(2);
 
 /// Initialize a new array of type `typ` of length `size`
 pub fn new_array(typ: Type, size: u64) -> Type {
diff --git a/src/ops/custom.rs b/src/ops/custom.rs
index 368d986c1..9302ee110 100644
--- a/src/ops/custom.rs
+++ b/src/ops/custom.rs
@@ -118,6 +118,11 @@ impl ExtensionOp {
     pub fn args(&self) -> &[TypeArg] {
         &self.args
     }
+
+    /// Returns a reference to the [`OpDef`] of this [`ExtensionOp`].
+    pub fn def(&self) -> &OpDef {
+        self.def.as_ref()
+    }
 }
 
 impl From<ExtensionOp> for OpaqueOp {
diff --git a/src/std_extensions/arithmetic/float_types.rs b/src/std_extensions/arithmetic/float_types.rs
index 8c56e2ad9..69ad19876 100644
--- a/src/std_extensions/arithmetic/float_types.rs
+++ b/src/std_extensions/arithmetic/float_types.rs
@@ -24,6 +24,14 @@ pub const FLOAT64_TYPE: Type = Type::new_extension(FLOAT64_CUSTOM_TYPE);
 /// A floating-point value.
 pub struct ConstF64(f64);
 
+impl std::ops::Deref for ConstF64 {
+    type Target = f64;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
 impl ConstF64 {
     /// Create a new [`ConstF64`]
     pub fn new(value: f64) -> Self {
diff --git a/src/std_extensions/quantum.rs b/src/std_extensions/quantum.rs
index 4f110b94f..d97ecc62f 100644
--- a/src/std_extensions/quantum.rs
+++ b/src/std_extensions/quantum.rs
@@ -4,6 +4,7 @@ use smol_str::SmolStr;
 
 use crate::extension::prelude::{BOOL_T, QB_T};
 use crate::extension::{ExtensionSet, SignatureError};
+use crate::std_extensions::arithmetic::float_types::FLOAT64_TYPE;
 use crate::type_row;
 use crate::types::type_param::TypeArg;
 use crate::types::TypeRow;
@@ -36,6 +37,20 @@ fn extension() -> Extension {
             one_qb_func,
         )
         .unwrap();
+    extension
+        .add_op_custom_sig_simple(
+            SmolStr::new_inline("RzF64"),
+            "Rotation specified by float".into(),
+            vec![],
+            |_: &[_]| {
+                Ok((
+                    type_row![QB_T, FLOAT64_TYPE],
+                    type_row![QB_T],
+                    ExtensionSet::new(),
+                ))
+            },
+        )
+        .unwrap();
 
     extension
         .add_op_custom_sig_simple(SmolStr::new_inline("CX"), "CX".into(), vec![], two_qb_func)