diff --git a/packages/core/ios/Sources/DdTraceImplementation.swift b/packages/core/ios/Sources/DdTraceImplementation.swift
index 01762c61f..94d8cf418 100644
--- a/packages/core/ios/Sources/DdTraceImplementation.swift
+++ b/packages/core/ios/Sources/DdTraceImplementation.swift
@@ -44,14 +44,13 @@ public class DdTraceImplementation: NSObject {
     public func finishSpan(spanId: NSString, context: NSDictionary, timestampMs: Double, resolve:RCTPromiseResolveBlock, reject:RCTPromiseRejectBlock) -> Void {
         objc_sync_enter(self)
         let optionalSpan = spanDictionary.removeValue(forKey: spanId)
-        objc_sync_exit(self)
-
         if let span = optionalSpan {
             set(tags: castAttributesToSwift(context).mergeWithGlobalAttributes(), to: span)
             let timeIntervalSince1970: TimeInterval = timestampMs / 1_000
             span.finish(at: Date(timeIntervalSince1970: timeIntervalSince1970))
         }
-        
+        objc_sync_exit(self)
+
         resolve(nil)
     }
 
diff --git a/packages/core/ios/Tests/DdTraceTests.swift b/packages/core/ios/Tests/DdTraceTests.swift
index 6c86a6e92..5c7d11585 100644
--- a/packages/core/ios/Tests/DdTraceTests.swift
+++ b/packages/core/ios/Tests/DdTraceTests.swift
@@ -140,6 +140,10 @@ internal class DdTraceTests: XCTestCase {
     }
 
     func testTracingConcurrently() {
+        // It is possible and acceptable that a concurrent finishSpan resolve is called on a different thread before we get the lastResolveValue.
+        // This would override lastResolveValue to be `nil`. To avoid this, we use a different resolve.
+        func mockFinishResolve(args: Any?) {}
+
         let iterationCount = 30
         DispatchQueue.concurrentPerform(iterations: iterationCount) { iteration in
             tracer.startSpan(
@@ -150,7 +154,7 @@ internal class DdTraceTests: XCTestCase {
                 reject: mockReject
             )
             let spanID = lastResolveValue as! NSString
-            tracer.finishSpan(spanId: spanID, context: testTags, timestampMs: 100, resolve: mockResolve, reject: mockReject)
+            tracer.finishSpan(spanId: spanID, context: testTags, timestampMs: 100, resolve: mockFinishResolve, reject: mockReject)
         }
 
         XCTAssertEqual(mockNativeTracer.startedSpans.count, iterationCount, "\(mockNativeTracer.startedSpans)")