diff --git a/Schemas/configuration.json b/Schemas/configuration.json
index bffa63b7a..e18d4380b 100644
--- a/Schemas/configuration.json
+++ b/Schemas/configuration.json
@@ -24,7 +24,6 @@
                     "exp_did_enter_preload_skip_asm_layout",
                     "exp_dispatch_apply",
                     "exp_oom_bg_dealloc_disable",
-                    "exp_remove_textkit_initialising_lock"
                 ]
     		}
 		}
diff --git a/Source/ASExperimentalFeatures.h b/Source/ASExperimentalFeatures.h
index 7c2e84873..bec8614bb 100644
--- a/Source/ASExperimentalFeatures.h
+++ b/Source/ASExperimentalFeatures.h
@@ -28,10 +28,9 @@ typedef NS_OPTIONS(NSUInteger, ASExperimentalFeatures) {
   ASExperimentalDidEnterPreloadSkipASMLayout = 1 << 7,                      // exp_did_enter_preload_skip_asm_layout
   ASExperimentalDispatchApply = 1 << 8,                                     // exp_dispatch_apply
   ASExperimentalOOMBackgroundDeallocDisable = 1 << 9,                       // exp_oom_bg_dealloc_disable
-  ASExperimentalRemoveTextKitInitialisingLock = 1 << 10,                    // exp_remove_textkit_initialising_lock
-  ASExperimentalDrawingGlobal = 1 << 11,                                    // exp_drawing_global
-  ASExperimentalOptimizeDataControllerPipeline = 1 << 12,                   // exp_optimize_data_controller_pipeline
-  ASExperimentalTraitCollectionDidChangeWithPreviousCollection = 1 << 13,   // exp_trait_collection_did_change_with_previous_collection
+  ASExperimentalDrawingGlobal = 1 << 10,                                    // exp_drawing_global
+  ASExperimentalOptimizeDataControllerPipeline = 1 << 11,                   // exp_optimize_data_controller_pipeline
+  ASExperimentalTraitCollectionDidChangeWithPreviousCollection = 1 << 12,   // exp_trait_collection_did_change_with_previous_collection
   ASExperimentalFeatureAll = 0xFFFFFFFF
 };
 
diff --git a/Source/ASExperimentalFeatures.mm b/Source/ASExperimentalFeatures.mm
index 7637481bc..eb9848292 100644
--- a/Source/ASExperimentalFeatures.mm
+++ b/Source/ASExperimentalFeatures.mm
@@ -22,7 +22,6 @@
                                       @"exp_did_enter_preload_skip_asm_layout",
                                       @"exp_dispatch_apply",
                                       @"exp_oom_bg_dealloc_disable",
-                                      @"exp_remove_textkit_initialising_lock",
                                       @"exp_drawing_global",
                                       @"exp_optimize_data_controller_pipeline",
                                       @"exp_trait_collection_did_change_with_previous_collection"]));
diff --git a/Source/TextKit/ASTextKitContext.mm b/Source/TextKit/ASTextKitContext.mm
index e5b16a696..8c24644d4 100644
--- a/Source/TextKit/ASTextKitContext.mm
+++ b/Source/TextKit/ASTextKitContext.mm
@@ -37,9 +37,7 @@ - (instancetype)initWithAttributedString:(NSAttributedString *)attributedString
     static dispatch_once_t onceToken;
     // Concurrently initialising TextKit components crashes (rdar://18448377) so we use a global lock.
     dispatch_once(&onceToken, ^{
-      if (!ASActivateExperimentalFeature(ASExperimentalRemoveTextKitInitialisingLock)) {
         mutex = new AS::Mutex();
-      }
     });
     if (mutex != NULL) {
       mutex->lock();
diff --git a/Tests/ASConfigurationTests.mm b/Tests/ASConfigurationTests.mm
index c5e533e22..a0eefcaa2 100644
--- a/Tests/ASConfigurationTests.mm
+++ b/Tests/ASConfigurationTests.mm
@@ -28,7 +28,6 @@
   ASExperimentalDidEnterPreloadSkipASMLayout,
   ASExperimentalDispatchApply,
   ASExperimentalOOMBackgroundDeallocDisable,
-  ASExperimentalRemoveTextKitInitialisingLock,
   ASExperimentalDrawingGlobal,
   ASExperimentalOptimizeDataControllerPipeline
 };
@@ -53,7 +52,6 @@ + (NSArray *)names {
     @"exp_did_enter_preload_skip_asm_layout",
     @"exp_dispatch_apply",
     @"exp_oom_bg_dealloc_disable",
-    @"exp_remove_textkit_initialising_lock",
     @"exp_drawing_global",
     @"exp_optimize_data_controller_pipeline"
   ];