diff --git a/src/builder/cfg.rs b/src/builder/cfg.rs
index 153d367f0..18855abd0 100644
--- a/src/builder/cfg.rs
+++ b/src/builder/cfg.rs
@@ -73,7 +73,7 @@ impl HugrBuilder for CFGBuilder<Hugr> {
         mut self,
         extension_registry: &ExtensionRegistry,
     ) -> Result<Hugr, crate::hugr::ValidationError> {
-        self.base.infer_and_validate(extension_registry)?;
+        self.base.update_validate(extension_registry)?;
         Ok(self.base)
     }
 }
diff --git a/src/builder/conditional.rs b/src/builder/conditional.rs
index b42167ff9..54076b3ce 100644
--- a/src/builder/conditional.rs
+++ b/src/builder/conditional.rs
@@ -150,7 +150,7 @@ impl HugrBuilder for ConditionalBuilder<Hugr> {
         mut self,
         extension_registry: &ExtensionRegistry,
     ) -> Result<Hugr, crate::hugr::ValidationError> {
-        self.base.infer_and_validate(extension_registry)?;
+        self.base.update_validate(extension_registry)?;
         Ok(self.base)
     }
 }
diff --git a/src/builder/dataflow.rs b/src/builder/dataflow.rs
index 07c1e2f97..9088b3c5c 100644
--- a/src/builder/dataflow.rs
+++ b/src/builder/dataflow.rs
@@ -90,7 +90,7 @@ impl HugrBuilder for DFGBuilder<Hugr> {
         mut self,
         extension_registry: &ExtensionRegistry,
     ) -> Result<Hugr, ValidationError> {
-        self.base.infer_and_validate(extension_registry)?;
+        self.base.update_validate(extension_registry)?;
         Ok(self.base)
     }
 }
diff --git a/src/builder/module.rs b/src/builder/module.rs
index 2df7a1241..83b08a32c 100644
--- a/src/builder/module.rs
+++ b/src/builder/module.rs
@@ -60,7 +60,7 @@ impl HugrBuilder for ModuleBuilder<Hugr> {
         mut self,
         extension_registry: &ExtensionRegistry,
     ) -> Result<Hugr, ValidationError> {
-        self.0.infer_and_validate(extension_registry)?;
+        self.0.update_validate(extension_registry)?;
         Ok(self.0)
     }
 }
diff --git a/src/extension/infer.rs b/src/extension/infer.rs
index f1a08cff3..a1df4d4a1 100644
--- a/src/extension/infer.rs
+++ b/src/extension/infer.rs
@@ -867,7 +867,7 @@ mod test {
         // nodes and their parents and `report_mismatch` isn't yet smart enough
         // to handle that.
         assert_matches!(
-            hugr.infer_and_validate(&PRELUDE_REGISTRY),
+            hugr.update_validate(&PRELUDE_REGISTRY),
             Err(ValidationError::CantInfer(_))
         );
         Ok(())
@@ -1155,7 +1155,7 @@ mod test {
         for (src, tgt) in nodes.into_iter().tuple_windows() {
             hugr.connect(src, 0, tgt, 0)?;
         }
-        hugr.infer_and_validate(&PRELUDE_REGISTRY)?;
+        hugr.update_validate(&PRELUDE_REGISTRY)?;
         Ok(())
     }
 
@@ -1421,7 +1421,7 @@ mod test {
         hugr.connect(bb1, 0, bb2, 0)?;
         hugr.connect(bb2, 0, exit, 0)?;
 
-        hugr.infer_and_validate(&PRELUDE_REGISTRY)?;
+        hugr.update_validate(&PRELUDE_REGISTRY)?;
 
         Ok(())
     }
@@ -1520,7 +1520,7 @@ mod test {
 
         for (bb0, bb1, bb2) in variants.into_iter() {
             let mut hugr = make_looping_cfg(bb0, bb1, bb2)?;
-            hugr.infer_and_validate(&PRELUDE_REGISTRY)?;
+            hugr.update_validate(&PRELUDE_REGISTRY)?;
         }
         Ok(())
     }
@@ -1573,7 +1573,7 @@ mod test {
         hugr.connect(bb, 0, bb, 0)?;
         hugr.connect(bb, 0, exit, 0)?;
 
-        hugr.infer_and_validate(&PRELUDE_REGISTRY)?;
+        hugr.update_validate(&PRELUDE_REGISTRY)?;
 
         Ok(())
     }
diff --git a/src/hugr.rs b/src/hugr.rs
index 6f9bb4b27..ec5926fb9 100644
--- a/src/hugr.rs
+++ b/src/hugr.rs
@@ -29,6 +29,7 @@ pub use self::views::{HugrView, RootTagged};
 use crate::extension::{
     infer_extensions, ExtensionRegistry, ExtensionSet, ExtensionSolution, InferExtensionError,
 };
+use crate::ops::custom::resolve_extension_ops;
 use crate::ops::{OpTag, OpTrait, OpType, DEFAULT_OPTYPE};
 use crate::types::{FunctionType, Signature};
 
@@ -230,11 +231,12 @@ pub type Direction = portgraph::Direction;
 
 /// Public API for HUGRs.
 impl Hugr {
-    /// Run resource inference and pass the closure into validation
-    pub fn infer_and_validate(
+    /// Resolve extension ops, infer extensions used, and pass the closure into validation
+    pub fn update_validate(
         &mut self,
         extension_registry: &ExtensionRegistry,
     ) -> Result<(), ValidationError> {
+        resolve_extension_ops(self, extension_registry)?;
         let closure = self.infer_extensions()?;
         self.validate_with_extension_closure(closure, extension_registry)?;
         Ok(())
diff --git a/src/hugr/rewrite/insert_identity.rs b/src/hugr/rewrite/insert_identity.rs
index 28f1c6529..cf4e12a70 100644
--- a/src/hugr/rewrite/insert_identity.rs
+++ b/src/hugr/rewrite/insert_identity.rs
@@ -146,7 +146,7 @@ mod tests {
 
         assert_eq!(noop, LeafOp::Noop { ty: QB_T });
 
-        h.infer_and_validate(&PRELUDE_REGISTRY).unwrap();
+        h.update_validate(&PRELUDE_REGISTRY).unwrap();
     }
 
     #[test]
diff --git a/src/hugr/rewrite/outline_cfg.rs b/src/hugr/rewrite/outline_cfg.rs
index c01f28c18..691fb8a40 100644
--- a/src/hugr/rewrite/outline_cfg.rs
+++ b/src/hugr/rewrite/outline_cfg.rs
@@ -301,7 +301,7 @@ mod test {
     #[test]
     fn test_outline_cfg() {
         let (mut h, head, tail) = build_conditional_in_loop_cfg(false).unwrap();
-        h.infer_and_validate(&PRELUDE_REGISTRY).unwrap();
+        h.update_validate(&PRELUDE_REGISTRY).unwrap();
         do_outline_cfg_test(&mut h, head, tail, 1);
         h.validate(&PRELUDE_REGISTRY).unwrap();
     }
diff --git a/src/hugr/rewrite/simple_replace.rs b/src/hugr/rewrite/simple_replace.rs
index 9a8393ace..53e3f68a7 100644
--- a/src/hugr/rewrite/simple_replace.rs
+++ b/src/hugr/rewrite/simple_replace.rs
@@ -416,7 +416,7 @@ pub(in crate::hugr::rewrite) mod test {
         // ├───┤├───┤┌─┴─┐
         // ┤ H ├┤ H ├┤ X ├
         // └───┘└───┘└───┘
-        assert_eq!(h.infer_and_validate(&PRELUDE_REGISTRY), Ok(()));
+        assert_eq!(h.update_validate(&PRELUDE_REGISTRY), Ok(()));
     }
 
     #[rstest]
@@ -488,7 +488,7 @@ pub(in crate::hugr::rewrite) mod test {
         // ├───┤├───┤┌───┐
         // ┤ H ├┤ H ├┤ H ├
         // └───┘└───┘└───┘
-        assert_eq!(h.infer_and_validate(&PRELUDE_REGISTRY), Ok(()));
+        assert_eq!(h.update_validate(&PRELUDE_REGISTRY), Ok(()));
     }
 
     #[test]
diff --git a/src/hugr/serialize.rs b/src/hugr/serialize.rs
index 89b2da36f..2fdc2fb36 100644
--- a/src/hugr/serialize.rs
+++ b/src/hugr/serialize.rs
@@ -470,7 +470,7 @@ pub mod test {
         hugr.connect(new_in, 0, out, 0).unwrap();
         hugr.move_before_sibling(new_in, old_in).unwrap();
         hugr.remove_node(old_in).unwrap();
-        hugr.infer_and_validate(&PRELUDE_REGISTRY).unwrap();
+        hugr.update_validate(&PRELUDE_REGISTRY).unwrap();
 
         let ser = serde_json::to_vec(&hugr).unwrap();
         let new_hugr: Hugr = serde_json::from_slice(&ser).unwrap();
diff --git a/src/hugr/validate.rs b/src/hugr/validate.rs
index c16cae8e1..3338c081a 100644
--- a/src/hugr/validate.rs
+++ b/src/hugr/validate.rs
@@ -1113,20 +1113,20 @@ mod test {
         h.connect(sub_dfg, 0, output, 0)?;
 
         assert_matches!(
-            h.infer_and_validate(&EMPTY_REG),
+            h.update_validate(&EMPTY_REG),
             Err(ValidationError::UnconnectedPort { .. })
         );
 
         h.connect(input, 1, sub_op, 1)?;
         assert_matches!(
-            h.infer_and_validate(&EMPTY_REG),
+            h.update_validate(&EMPTY_REG),
             Err(ValidationError::InterGraphEdgeError(
                 InterGraphEdgeError::MissingOrderEdge { .. }
             ))
         );
         //Order edge. This will need metadata indicating its purpose.
         h.add_other_edge(input, sub_dfg)?;
-        h.infer_and_validate(&EMPTY_REG).unwrap();
+        h.update_validate(&EMPTY_REG).unwrap();
         Ok(())
     }
 
@@ -1143,7 +1143,7 @@ mod test {
         h.connect(input, 0, and, 0)?;
         h.connect(and, 0, output, 0)?;
         assert_eq!(
-            h.infer_and_validate(&EMPTY_REG),
+            h.update_validate(&EMPTY_REG),
             Err(ValidationError::UnconnectedPort {
                 node: and,
                 port: Port::new_incoming(1),
@@ -1161,7 +1161,7 @@ mod test {
         h.connect(cst, 0, lcst, 0)?;
         h.connect(lcst, 0, and, 1)?;
         // There is no edge from Input to LoadConstant, but that's OK:
-        h.infer_and_validate(&EMPTY_REG).unwrap();
+        h.update_validate(&EMPTY_REG).unwrap();
         Ok(())
     }
 
diff --git a/src/hugr/views/sibling.rs b/src/hugr/views/sibling.rs
index 4829a2418..4311afb2d 100644
--- a/src/hugr/views/sibling.rs
+++ b/src/hugr/views/sibling.rs
@@ -437,9 +437,7 @@ mod test {
 
     #[rstest]
     fn flat_mut(mut simple_dfg_hugr: Hugr) {
-        simple_dfg_hugr
-            .infer_and_validate(&PRELUDE_REGISTRY)
-            .unwrap();
+        simple_dfg_hugr.update_validate(&PRELUDE_REGISTRY).unwrap();
         let root = simple_dfg_hugr.root();
         let signature = simple_dfg_hugr.get_function_type().unwrap().clone();