diff --git a/.github/workflows/rust-check.yml b/.github/workflows/rust-check.yml
index 352fc9a29..9fc83d74b 100644
--- a/.github/workflows/rust-check.yml
+++ b/.github/workflows/rust-check.yml
@@ -91,6 +91,8 @@ jobs:
           tool: nextest
       - name: Test workspace (Windows, nextest per-process isolation)
         if: runner.os == 'Windows'
+        env:
+          OP_TEST_ESTIMATE_TEXT_MEASURE: "1"
         run: cargo nextest run --workspace --test-threads=1
       - name: Doctests (Windows)
         if: runner.os == 'Windows'
diff --git a/.github/workflows/rust-multiplatform.yml b/.github/workflows/rust-multiplatform.yml
index ea23083d3..675714371 100644
--- a/.github/workflows/rust-multiplatform.yml
+++ b/.github/workflows/rust-multiplatform.yml
@@ -132,6 +132,8 @@ jobs:
           tool: nextest
       - name: Test (host, Windows — nextest per-process isolation)
         if: matrix.cross == false && matrix.check_only != true && runner.os == 'Windows'
+        env:
+          OP_TEST_ESTIMATE_TEXT_MEASURE: "1"
         run: cargo nextest run --workspace --target ${{ matrix.target }} --test-threads=1
       - name: Doctests (host, Windows)
         if: matrix.cross == false && matrix.check_only != true && runner.os == 'Windows'
diff --git a/crates/op-pen-loader/src/adapter.rs b/crates/op-pen-loader/src/adapter.rs
index 37ab5a21d..304906484 100644
--- a/crates/op-pen-loader/src/adapter.rs
+++ b/crates/op-pen-loader/src/adapter.rs
@@ -60,8 +60,13 @@ thread_local! {
 /// and repeat reconversions (drag / resize / colour edits) re-measure identical
 /// text, so the cache turns those into hash lookups. (The estimate backend below
 /// is already cheap, so it is left unwrapped.)
-#[cfg(all(feature = "skia-measure", not(all(test, target_os = "windows"))))]
+#[cfg(feature = "skia-measure")]
 fn make_measure_backend() -> Rc<dyn MeasureBackend> {
+    // Windows CI sets this for tests that load op-pen-loader as a dependency.
+    if cfg!(target_os = "windows") && std::env::var_os("OP_TEST_ESTIMATE_TEXT_MEASURE").is_some() {
+        return jian_core::layout::measure::default_backend();
+    }
+
     Rc::new(crate::measure_cache::CachingMeasureBackend::new(Rc::new(
         jian_skia::SkiaMeasure::new(),
     )))
@@ -71,7 +76,7 @@ fn make_measure_backend() -> Rc<dyn MeasureBackend> {
 /// skia-safe. It is a character-count heuristic (~10% width error); the
 /// CanvasKit backend re-measures glyphs exactly at paint time, so layout drift
 /// is bounded to flex sizing of unconstrained text.
-#[cfg(any(not(feature = "skia-measure"), all(test, target_os = "windows")))]
+#[cfg(not(feature = "skia-measure"))]
 fn make_measure_backend() -> Rc<dyn MeasureBackend> {
     jian_core::layout::measure::default_backend()
 }