diff --git a/Foundation/NSCalendar.swift b/Foundation/NSCalendar.swift
index e3b427f19e..b14ce2778d 100644
--- a/Foundation/NSCalendar.swift
+++ b/Foundation/NSCalendar.swift
@@ -583,8 +583,9 @@ open class NSCalendar : NSObject, NSCopying, NSSecureCoding {
         var at: CFAbsoluteTime = date.timeIntervalSinceReferenceDate
         
         let res: Bool = withUnsafeMutablePointer(to: &at) { t in
+            let count = Int32(vector.count)
             return vector.withUnsafeMutableBufferPointer { (vectorBuffer: inout UnsafeMutableBufferPointer<Int32>) in
-                return _CFCalendarAddComponentsV(_cfObject, t, CFOptionFlags(opts.rawValue), compDesc, vectorBuffer.baseAddress!, Int32(vector.count))
+                return _CFCalendarAddComponentsV(_cfObject, t, CFOptionFlags(opts.rawValue), compDesc, vectorBuffer.baseAddress!, count)
             }
         }
         
@@ -603,8 +604,9 @@ open class NSCalendar : NSObject, NSCopying, NSSecureCoding {
                 return intArrayBuffer.baseAddress!.advanced(by: idx)
             }
 
+            let count = Int32(vector.count)
             return vector.withUnsafeMutableBufferPointer { (vecBuffer: inout UnsafeMutableBufferPointer<UnsafeMutablePointer<Int32>>) in
-                return _CFCalendarGetComponentDifferenceV(_cfObject, startingDate.timeIntervalSinceReferenceDate, resultDate.timeIntervalSinceReferenceDate, CFOptionFlags(opts.rawValue), compDesc, vecBuffer.baseAddress!, Int32(vector.count))
+                return _CFCalendarGetComponentDifferenceV(_cfObject, startingDate.timeIntervalSinceReferenceDate, resultDate.timeIntervalSinceReferenceDate, CFOptionFlags(opts.rawValue), compDesc, vecBuffer.baseAddress!, count)
             }
         }
         if res {
diff --git a/TestFoundation/TestNSData.swift b/TestFoundation/TestNSData.swift
index 221daa35e8..510ff85d4a 100644
--- a/TestFoundation/TestNSData.swift
+++ b/TestFoundation/TestNSData.swift
@@ -930,11 +930,11 @@ extension TestNSData {
             // Mutate it
             bytes.pointee = 0x67
             XCTAssertEqual(bytes.pointee, 0x67, "First byte should be 0x67")
-            XCTAssertEqual(mutatingHello[0], 0x67, "First byte accessed via other method should still be 0x67")
-            
-            // Verify that the first data is still correct
-            XCTAssertEqual(hello[0], 0x68, "The first byte should still be 0x68")
         }
+        XCTAssertEqual(mutatingHello[0], 0x67, "First byte accessed via other method should still be 0x67")
+
+        // Verify that the first data is still correct
+        XCTAssertEqual(hello[0], 0x68, "The first byte should still be 0x68")
     }