diff --git a/framework-crates/objc2-core-foundation/src/geometry.rs b/framework-crates/objc2-core-foundation/src/geometry.rs
index e93fab3f2..29836ff3a 100644
--- a/framework-crates/objc2-core-foundation/src/geometry.rs
+++ b/framework-crates/objc2-core-foundation/src/geometry.rs
@@ -246,7 +246,8 @@ impl CGRect {
     #[doc(alias = "CGRectZero")]
     pub const ZERO: Self = Self::new(CGPoint::ZERO, CGSize::ZERO);
 
-    /// Returns a rectangle with a positive width and height.
+    /// Returns a rectangle with a nonnegative width and height, moving the
+    /// origin to preserve the rectangle's extent.
     ///
     ///
     /// # Examples
@@ -256,13 +257,39 @@ impl CGRect {
     /// let origin = CGPoint::new(1.0, 1.0);
     /// let size = CGSize::new(-5.0, -2.0);
     /// let rect = CGRect::new(origin, size);
-    /// assert_eq!(rect.standardize().size, CGSize::new(5.0, 2.0));
+    /// assert_eq!(
+    ///     rect.standardize(),
+    ///     CGRect::new(CGPoint::new(-4.0, -1.0), CGSize::new(5.0, 2.0)),
+    /// );
     /// ```
     #[inline]
     #[doc(alias = "CGRectStandardize")]
     #[cfg(feature = "std")] // `abs` only available in core since Rust 1.85
     pub fn standardize(self) -> Self {
-        Self::new(self.origin, self.size.abs())
+        if self.origin.x == CGFloat::INFINITY || self.origin.y == CGFloat::INFINITY {
+            return Self::new(
+                CGPoint::new(CGFloat::INFINITY, CGFloat::INFINITY),
+                CGSize::ZERO,
+            );
+        }
+        // Always add the offset, including signed zero, as CGRectStandardize does.
+        Self::new(
+            CGPoint::new(
+                self.origin.x
+                    + if self.size.width <= 0.0 {
+                        self.size.width
+                    } else {
+                        0.0
+                    },
+                self.origin.y
+                    + if self.size.height <= 0.0 {
+                        self.size.height
+                    } else {
+                        0.0
+                    },
+            ),
+            self.size.abs(),
+        )
     }
 
     /// The smallest coordinate of the rectangle.
@@ -301,7 +328,7 @@ impl CGRect {
         )
     }
 
-    /// Returns whether a rectangle has zero width or height.
+    /// Returns whether a rectangle has zero width or height, or is null.
     ///
     ///
     /// # Examples
@@ -316,9 +343,10 @@ impl CGRect {
     #[inline]
     #[doc(alias = "CGRectIsEmpty")]
     pub fn is_empty(self) -> bool {
-        !(self.size.width > 0.0 && self.size.height > 0.0)
-        // TODO: NaN handling?
-        // self.size.width <= 0.0 || self.size.height <= 0.0
+        self.size.width == 0.0
+            || self.size.height == 0.0
+            || self.origin.x == CGFloat::INFINITY
+            || self.origin.y == CGFloat::INFINITY
     }
 
     // TODO: NSContainsRect / CGRectContainsRect
diff --git a/framework-crates/objc2-core-graphics/Cargo.modified.toml b/framework-crates/objc2-core-graphics/Cargo.modified.toml
new file mode 100644
index 000000000..ef0ef80f1
--- /dev/null
+++ b/framework-crates/objc2-core-graphics/Cargo.modified.toml
@@ -0,0 +1,2 @@
+[dev-dependencies]
+objc2-core-foundation = { workspace = true, features = ["std"] }
diff --git a/framework-crates/objc2-core-graphics/Cargo.toml b/framework-crates/objc2-core-graphics/Cargo.toml
index 446355490..86fed9876 100644
--- a/framework-crates/objc2-core-graphics/Cargo.toml
+++ b/framework-crates/objc2-core-graphics/Cargo.toml
@@ -262,3 +262,6 @@ CGWindow = [
     "objc2-core-foundation/CFDictionary",
 ]
 CGWindowLevel = []
+
+[dev-dependencies]
+objc2-core-foundation = { workspace = true, features = ["std"] }
diff --git a/framework-crates/objc2-core-graphics/tests/geometry.rs b/framework-crates/objc2-core-graphics/tests/geometry.rs
new file mode 100644
index 000000000..71584a75b
--- /dev/null
+++ b/framework-crates/objc2-core-graphics/tests/geometry.rs
@@ -0,0 +1,48 @@
+#![cfg(feature = "CGGeometry")]
+#![cfg(feature = "std")]
+#![cfg(target_vendor = "apple")]
+
+use objc2_core_foundation::{CGFloat, CGPoint, CGRect, CGSize};
+use objc2_core_graphics::{CGRectIsEmpty, CGRectStandardize};
+
+#[test]
+fn rectangle_helpers_match_core_graphics() {
+    let values = [
+        CGFloat::NEG_INFINITY,
+        -CGFloat::MAX,
+        -5.0,
+        -CGFloat::MIN_POSITIVE,
+        -0.0,
+        0.0,
+        CGFloat::MIN_POSITIVE,
+        5.0,
+        CGFloat::MAX,
+        CGFloat::INFINITY,
+        CGFloat::NAN,
+    ];
+    for x in values {
+        for y in values {
+            for width in values {
+                for height in values {
+                    let rect = CGRect::new(CGPoint::new(x, y), CGSize::new(width, height));
+                    assert_eq!(rect.is_empty(), CGRectIsEmpty(rect), "{rect:?}");
+                    let actual = rect.standardize();
+                    let expected = CGRectStandardize(rect);
+                    for (actual, expected) in [
+                        (actual.origin.x, expected.origin.x),
+                        (actual.origin.y, expected.origin.y),
+                        (actual.size.width, expected.size.width),
+                        (actual.size.height, expected.size.height),
+                    ] {
+                        // NaN has no equality relation, but must remain NaN.
+                        assert!(
+                            actual.to_bits() == expected.to_bits()
+                                || (actual.is_nan() && expected.is_nan()),
+                            "{rect:?}: expected {expected:?}, got {actual:?}",
+                        );
+                    }
+                }
+            }
+        }
+    }
+}