diff --git a/test_files/guppy_optimization/angles/angles.flat.hugr b/test_files/guppy_optimization/angles/angles.flat.hugr
index e7207da5e..ce74274a8 100644
Binary files a/test_files/guppy_optimization/angles/angles.flat.hugr and b/test_files/guppy_optimization/angles/angles.flat.hugr differ
diff --git a/test_files/guppy_optimization/angles/angles.flat.py b/test_files/guppy_optimization/angles/angles.flat.py
index 33c0daf66..701cfbc72 100644
--- a/test_files/guppy_optimization/angles/angles.flat.py
+++ b/test_files/guppy_optimization/angles/angles.flat.py
@@ -1,7 +1,7 @@
 # /// script
 # requires-python = ">=3.13"
 # dependencies = [
-#     "guppylang >=0.21.3",
+#     "guppylang >=0.21.6",
 # ]
 # ///
 
diff --git a/test_files/guppy_optimization/angles/angles.hugr b/test_files/guppy_optimization/angles/angles.hugr
index dde9b4652..2a143ab61 100644
Binary files a/test_files/guppy_optimization/angles/angles.hugr and b/test_files/guppy_optimization/angles/angles.hugr differ
diff --git a/test_files/guppy_optimization/angles/angles.opt.hugr b/test_files/guppy_optimization/angles/angles.opt.hugr
index 7b6a1f144..cd925f38d 100644
Binary files a/test_files/guppy_optimization/angles/angles.opt.hugr and b/test_files/guppy_optimization/angles/angles.opt.hugr differ
diff --git a/test_files/guppy_optimization/angles/angles.opt.py b/test_files/guppy_optimization/angles/angles.opt.py
index 678b3f20f..65f27cac0 100644
--- a/test_files/guppy_optimization/angles/angles.opt.py
+++ b/test_files/guppy_optimization/angles/angles.opt.py
@@ -1,7 +1,7 @@
 # /// script
 # requires-python = ">=3.13"
 # dependencies = [
-#     "guppylang >=0.21.3",
+#     "guppylang >=0.21.6",
 # ]
 # ///
 
diff --git a/test_files/guppy_optimization/angles/angles.py b/test_files/guppy_optimization/angles/angles.py
index d7e5540f2..0a8824423 100644
--- a/test_files/guppy_optimization/angles/angles.py
+++ b/test_files/guppy_optimization/angles/angles.py
@@ -1,7 +1,7 @@
 # /// script
 # requires-python = ">=3.13"
 # dependencies = [
-#     "guppylang >=0.21.3",
+#     "guppylang >=0.21.6",
 # ]
 # ///
 
diff --git a/test_files/guppy_optimization/false_branch/false_branch.hugr b/test_files/guppy_optimization/false_branch/false_branch.hugr
index fe5287546..36c5d0e70 100644
Binary files a/test_files/guppy_optimization/false_branch/false_branch.hugr and b/test_files/guppy_optimization/false_branch/false_branch.hugr differ
diff --git a/test_files/guppy_optimization/false_branch/false_branch.opt.hugr b/test_files/guppy_optimization/false_branch/false_branch.opt.hugr
index 7b6a1f144..cd925f38d 100644
Binary files a/test_files/guppy_optimization/false_branch/false_branch.opt.hugr and b/test_files/guppy_optimization/false_branch/false_branch.opt.hugr differ
diff --git a/test_files/guppy_optimization/false_branch/false_branch.opt.py b/test_files/guppy_optimization/false_branch/false_branch.opt.py
index 678b3f20f..65f27cac0 100644
--- a/test_files/guppy_optimization/false_branch/false_branch.opt.py
+++ b/test_files/guppy_optimization/false_branch/false_branch.opt.py
@@ -1,7 +1,7 @@
 # /// script
 # requires-python = ">=3.13"
 # dependencies = [
-#     "guppylang >=0.21.3",
+#     "guppylang >=0.21.6",
 # ]
 # ///
 
diff --git a/test_files/guppy_optimization/false_branch/false_branch.py b/test_files/guppy_optimization/false_branch/false_branch.py
index 4479dae8b..c1b4bac85 100644
--- a/test_files/guppy_optimization/false_branch/false_branch.py
+++ b/test_files/guppy_optimization/false_branch/false_branch.py
@@ -1,7 +1,7 @@
 # /// script
 # requires-python = ">=3.13"
 # dependencies = [
-#     "guppylang >=0.21.3",
+#     "guppylang >=0.21.6",
 # ]
 # ///
 
diff --git a/test_files/guppy_optimization/nested/nested.flat.hugr b/test_files/guppy_optimization/nested/nested.flat.hugr
index 5c8eb3a8e..b5356bd1d 100644
Binary files a/test_files/guppy_optimization/nested/nested.flat.hugr and b/test_files/guppy_optimization/nested/nested.flat.hugr differ
diff --git a/test_files/guppy_optimization/nested/nested.flat.py b/test_files/guppy_optimization/nested/nested.flat.py
index d2f602cde..81bccc182 100644
--- a/test_files/guppy_optimization/nested/nested.flat.py
+++ b/test_files/guppy_optimization/nested/nested.flat.py
@@ -1,7 +1,7 @@
 # /// script
 # requires-python = ">=3.13"
 # dependencies = [
-#     "guppylang >=0.21.3",
+#     "guppylang >=0.21.6",
 # ]
 # ///
 
diff --git a/test_files/guppy_optimization/nested/nested.hugr b/test_files/guppy_optimization/nested/nested.hugr
index 09784e2ae..f5ec927c2 100644
Binary files a/test_files/guppy_optimization/nested/nested.hugr and b/test_files/guppy_optimization/nested/nested.hugr differ
diff --git a/test_files/guppy_optimization/nested/nested.opt.hugr b/test_files/guppy_optimization/nested/nested.opt.hugr
index c951fcaf6..2407e5276 100644
Binary files a/test_files/guppy_optimization/nested/nested.opt.hugr and b/test_files/guppy_optimization/nested/nested.opt.hugr differ
diff --git a/test_files/guppy_optimization/nested/nested.opt.py b/test_files/guppy_optimization/nested/nested.opt.py
index e495268e3..337f797b7 100644
--- a/test_files/guppy_optimization/nested/nested.opt.py
+++ b/test_files/guppy_optimization/nested/nested.opt.py
@@ -1,7 +1,7 @@
 # /// script
 # requires-python = ">=3.13"
 # dependencies = [
-#     "guppylang >=0.21.3",
+#     "guppylang >=0.21.6",
 # ]
 # ///
 
diff --git a/test_files/guppy_optimization/nested/nested.py b/test_files/guppy_optimization/nested/nested.py
index 7cbb2d509..b937f292b 100644
--- a/test_files/guppy_optimization/nested/nested.py
+++ b/test_files/guppy_optimization/nested/nested.py
@@ -1,7 +1,7 @@
 # /// script
 # requires-python = ">=3.13"
 # dependencies = [
-#     "guppylang >=0.21.3",
+#     "guppylang >=0.21.6",
 # ]
 # ///
 
diff --git a/test_files/guppy_optimization/ranges/ranges.flat.hugr b/test_files/guppy_optimization/ranges/ranges.flat.hugr
index a9692f206..d1926fe03 100644
Binary files a/test_files/guppy_optimization/ranges/ranges.flat.hugr and b/test_files/guppy_optimization/ranges/ranges.flat.hugr differ
diff --git a/test_files/guppy_optimization/ranges/ranges.flat.py b/test_files/guppy_optimization/ranges/ranges.flat.py
index 917484737..16bfd960a 100644
--- a/test_files/guppy_optimization/ranges/ranges.flat.py
+++ b/test_files/guppy_optimization/ranges/ranges.flat.py
@@ -1,7 +1,7 @@
 # /// script
 # requires-python = ">=3.13"
 # dependencies = [
-#     "guppylang >=0.21.3",
+#     "guppylang >=0.21.6",
 # ]
 # ///
 
diff --git a/test_files/guppy_optimization/ranges/ranges.hugr b/test_files/guppy_optimization/ranges/ranges.hugr
index 58030688f..1108b73c8 100644
Binary files a/test_files/guppy_optimization/ranges/ranges.hugr and b/test_files/guppy_optimization/ranges/ranges.hugr differ
diff --git a/test_files/guppy_optimization/ranges/ranges.opt.hugr b/test_files/guppy_optimization/ranges/ranges.opt.hugr
index 1a1eb62a1..3e6feab4f 100644
Binary files a/test_files/guppy_optimization/ranges/ranges.opt.hugr and b/test_files/guppy_optimization/ranges/ranges.opt.hugr differ
diff --git a/test_files/guppy_optimization/ranges/ranges.opt.py b/test_files/guppy_optimization/ranges/ranges.opt.py
index a0b00774c..1f3a5cdd4 100644
--- a/test_files/guppy_optimization/ranges/ranges.opt.py
+++ b/test_files/guppy_optimization/ranges/ranges.opt.py
@@ -1,7 +1,7 @@
 # /// script
 # requires-python = ">=3.13"
 # dependencies = [
-#     "guppylang >=0.21.3",
+#     "guppylang >=0.21.6",
 # ]
 # ///
 
diff --git a/test_files/guppy_optimization/ranges/ranges.py b/test_files/guppy_optimization/ranges/ranges.py
index e7e9b6a58..8cfa2183c 100644
--- a/test_files/guppy_optimization/ranges/ranges.py
+++ b/test_files/guppy_optimization/ranges/ranges.py
@@ -1,7 +1,7 @@
 # /// script
 # requires-python = ">=3.13"
 # dependencies = [
-#     "guppylang >=0.21.3",
+#     "guppylang >=0.21.6",
 # ]
 # ///
 
diff --git a/test_files/guppy_optimization/simple_cx/simple_cx.hugr b/test_files/guppy_optimization/simple_cx/simple_cx.hugr
index 5acd2626e..71cadce8f 100644
Binary files a/test_files/guppy_optimization/simple_cx/simple_cx.hugr and b/test_files/guppy_optimization/simple_cx/simple_cx.hugr differ
diff --git a/test_files/guppy_optimization/simple_cx/simple_cx.opt.hugr b/test_files/guppy_optimization/simple_cx/simple_cx.opt.hugr
index 39984359d..1793f4081 100644
Binary files a/test_files/guppy_optimization/simple_cx/simple_cx.opt.hugr and b/test_files/guppy_optimization/simple_cx/simple_cx.opt.hugr differ
diff --git a/test_files/guppy_optimization/simple_cx/simple_cx.opt.py b/test_files/guppy_optimization/simple_cx/simple_cx.opt.py
index 3ec99a025..bdad0cb28 100644
--- a/test_files/guppy_optimization/simple_cx/simple_cx.opt.py
+++ b/test_files/guppy_optimization/simple_cx/simple_cx.opt.py
@@ -1,7 +1,7 @@
 # /// script
 # requires-python = ">=3.13"
 # dependencies = [
-#     "guppylang >=0.21.3",
+#     "guppylang >=0.21.6",
 # ]
 # ///
 
diff --git a/test_files/guppy_optimization/simple_cx/simple_cx.py b/test_files/guppy_optimization/simple_cx/simple_cx.py
index 0cfd75940..0bd517bbe 100644
--- a/test_files/guppy_optimization/simple_cx/simple_cx.py
+++ b/test_files/guppy_optimization/simple_cx/simple_cx.py
@@ -1,7 +1,7 @@
 # /// script
 # requires-python = ">=3.13"
 # dependencies = [
-#     "guppylang >=0.21.3",
+#     "guppylang >=0.21.6",
 # ]
 # ///
 
diff --git a/tket-qsystem/tests/guppy_opt.rs b/tket-qsystem/tests/guppy_opt.rs
index 440c524ae..5ee016a57 100644
--- a/tket-qsystem/tests/guppy_opt.rs
+++ b/tket-qsystem/tests/guppy_opt.rs
@@ -1,8 +1,11 @@
 //! Tests optimizing Guppy-generated programs.
 
+use smol_str::SmolStr;
+use std::collections::HashMap;
 use std::fs;
 use std::io::BufReader;
 use std::path::Path;
+use tket::extension::{TKET1_EXTENSION_ID, TKET_EXTENSION_ID};
 
 use hugr::algorithms::ComposablePass;
 use hugr::{Hugr, HugrView};
@@ -44,19 +47,46 @@ fn guppy_simple_cx() -> Hugr {
     load_guppy_circuit("simple_cx")
 }
 
+fn count_gates(h: &impl HugrView) -> HashMap<SmolStr, usize> {
+    let mut counts = HashMap::new();
+    for n in h.nodes() {
+        if let Some(eop) = h.get_optype(n).as_extension_op() {
+            if [TKET_EXTENSION_ID, TKET1_EXTENSION_ID].contains(eop.extension_id()) {
+                *counts.entry(eop.qualified_id()).or_default() += 1;
+            }
+        }
+    }
+    counts
+}
+
 /// Run some simple optimization passes on the guppy-generated HUGRs and validate the result.
 ///
 /// This test is intended to check the current status of the Guppy optimization passes.
 ///
 #[rstest]
-#[case::angles(guppy_angles())]
-#[case::false_branch(guppy_false_branch())]
-#[case::nested(guppy_nested())]
-#[case::ranges(guppy_ranges())]
-#[case::simple_cx(guppy_simple_cx())]
+#[case::angles(guppy_angles(), [
+    ("tket.quantum.H", 2), ("tket.quantum.QAlloc", 1), ("tket.quantum.Rz", 2), ("tket.quantum.MeasureFree", 1)
+])]
+#[case::false_branch(guppy_false_branch(), [
+    ("tket.quantum.H", 2), ("tket.quantum.QAlloc", 1), ("tket.quantum.MeasureFree", 1)
+])]
+#[case::nested(guppy_nested(), [
+    ("tket.quantum.CZ", 1), ("tket.quantum.H", 2), ("tket.quantum.QAlloc", 3), ("tket.quantum.MeasureFree", 3)
+])]
+#[case::ranges(guppy_ranges(), [
+    ("tket.quantum.QAlloc", 4), ("tket.quantum.MeasureFree", 4), ("tket.quantum.H", 2), ("tket.quantum.CX", 2)
+])]
+#[case::simple_cx(guppy_simple_cx(), [
+    ("tket.quantum.QAlloc", 2), ("tket.quantum.CX", 2), ("tket.quantum.MeasureFree", 2)
+])]
 #[cfg_attr(miri, ignore)] // Opening files is not supported in (isolated) miri
-fn optimise_guppy(#[case] mut hugr: Hugr) {
+fn optimise_guppy<'a>(
+    #[case] mut hugr: Hugr,
+    #[case] before: impl IntoIterator<Item = (&'a str, usize)>,
+) {
     NormalizeGuppy::default().run(&mut hugr).unwrap();
+    let before = before.into_iter().map(|(k, v)| (k.into(), v)).collect();
+    assert_eq!(count_gates(&hugr), before);
 
     // TODO: Run pytket passes here, and check that the circuit is as optimized as possible at this point.
     //