diff --git a/include/Foundation/NSProcessInfo.h b/include/Foundation/NSProcessInfo.h
index b3742a82e..f4d7b4d6d 100644
--- a/include/Foundation/NSProcessInfo.h
+++ b/include/Foundation/NSProcessInfo.h
@@ -50,6 +50,14 @@ NSOperatingSystemVersion;
 - (NSOperatingSystemVersion)operatingSystemVersion;
 - (BOOL)isOperatingSystemAtLeastVersion:(NSOperatingSystemVersion)version;
 
+typedef NS_ENUM(NSInteger, NSProcessInfoThermalState) {
+    NSProcessInfoThermalStateNominal = 0,
+    NSProcessInfoThermalStateFair = 1,
+    NSProcessInfoThermalStateSerious = 2,
+    NSProcessInfoThermalStateCritical = 3,
+};
+- (NSProcessInfoThermalState)thermalState;
+
 @end
 
 @interface NSProcessInfo (NSProcessInfoPlatform)
@@ -62,3 +70,5 @@ NSOperatingSystemVersion;
 #ifdef DARLING
 FOUNDATION_EXPORT void __NSInitializeProcess(int argc,const char *argv[]);
 #endif
+
+FOUNDATION_EXPORT NSString *const NSProcessInfoThermalStateDidChangeNotification;
diff --git a/include/Foundation/NSUserActivity.h b/include/Foundation/NSUserActivity.h
index 80c92bc07..2a80df649 100644
--- a/include/Foundation/NSUserActivity.h
+++ b/include/Foundation/NSUserActivity.h
@@ -21,3 +21,5 @@
 
 @interface NSUserActivity : NSObject
 @end
+
+FOUNDATION_EXPORT NSString *const NSUserActivityTypeBrowsingWeb;
diff --git a/src/NSProcessInfo.m b/src/NSProcessInfo.m
index 1c21f176d..f9f354c80 100644
--- a/src/NSProcessInfo.m
+++ b/src/NSProcessInfo.m
@@ -305,6 +305,13 @@ SINGLETON_RR()
     return t.tv_sec + t.tv_usec / (NSTimeInterval)USEC_PER_SEC;
 }
 
+- (NSProcessInfoThermalState)thermalState
+{
+    /* No thermal-pressure source on Linux; report Nominal so clients
+     * (e.g. Chromium's ThermalStateObserverMac) proceed normally. */
+    return NSProcessInfoThermalStateNominal;
+}
+
 - (NSOperatingSystemVersion)operatingSystemVersion
 {
 	NSOperatingSystemVersion version = { 0, 0, 0 };
@@ -396,3 +403,5 @@ void __NSInitializeProcess(int argc,const char *argv[]) {
     }
 }
 #endif
+
+NSString *const NSProcessInfoThermalStateDidChangeNotification = @"NSProcessInfoThermalStateDidChangeNotification";
diff --git a/src/NSUserActivity.m b/src/NSUserActivity.m
index 09c0a732b..53649d20b 100644
--- a/src/NSUserActivity.m
+++ b/src/NSUserActivity.m
@@ -34,3 +34,5 @@
 }
 
 @end
+
+NSString *const NSUserActivityTypeBrowsingWeb = @"com.apple.coreservices.useractivity.browser";