diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2552aba6..ee307553 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -145,6 +145,13 @@ jobs:
     - name: Build crate
       run: cargo $CMD build $OPTIONS
 
+    # Test only on Linux x86_64, so we avoid spending unnecessary CI hours.
+    - name: Test dpi crate
+      if: >
+        contains(matrix.platform.name, 'Linux 64bit') &&
+        matrix.toolchain != '1.70.0'
+      run: cargo test -p dpi
+
     - name: Build tests
       if: >
         !contains(matrix.platform.target, 'redox') &&
diff --git a/dpi/src/lib.rs b/dpi/src/lib.rs
index 0faf475f..9258de30 100644
--- a/dpi/src/lib.rs
+++ b/dpi/src/lib.rs
@@ -250,7 +250,7 @@ impl<P: Pixel> PhysicalUnit<P> {
     #[inline]
     pub fn to_logical<X: Pixel>(&self, scale_factor: f64) -> LogicalUnit<X> {
         assert!(validate_scale_factor(scale_factor));
-        LogicalUnit::new(self.0.into() * scale_factor).cast()
+        LogicalUnit::new(self.0.into() / scale_factor).cast()
     }
 
     #[inline]