diff --git a/browser/installer/Makefile.in b/browser/installer/Makefile.in
index 5d365bd6a4c8..e8619ca0a33b 100644
--- a/browser/installer/Makefile.in
+++ b/browser/installer/Makefile.in
@@ -102,10 +102,6 @@ ifdef MOZ_NOTIFICATION_SERVER
 DEFINES += -DMOZ_NOTIFICATION_SERVER=1
 endif
 
-ifdef MOZ_BACKGROUNDTASKS
-DEFINES += -DMOZ_BACKGROUNDTASKS=1
-endif
-
 ifeq (cocoa,$(MOZ_WIDGET_TOOLKIT))
 MOZ_PKG_MAC_DSSTORE=$(topsrcdir)/$(MOZ_BRANDING_DIRECTORY)/dsstore
 MOZ_PKG_MAC_BACKGROUND=$(topsrcdir)/$(MOZ_BRANDING_DIRECTORY)/background.png
diff --git a/browser/moz.build b/browser/moz.build
index 9dfb4271d4c2..6e1665037457 100644
--- a/browser/moz.build
+++ b/browser/moz.build
@@ -48,9 +48,6 @@ for cdm in CONFIG["MOZ_EME_MODULES"]:
 if CONFIG["MOZ_GPSD"]:
     DEFINES["MOZ_GPSD"] = True
 
-if CONFIG["MOZ_BACKGROUNDTASKS"]:
-    DEFINES["MOZ_BACKGROUNDTASKS"] = True
-
 if CONFIG["MOZ_UPDATE_AGENT"]:
     DEFINES["MOZ_UPDATE_AGENT"] = True
 
diff --git a/modules/libpref/moz.build b/modules/libpref/moz.build
index 8ed2ca5db2d1..abd65be41b47 100644
--- a/modules/libpref/moz.build
+++ b/modules/libpref/moz.build
@@ -175,7 +175,4 @@ else:
         "greprefs.js",
     ]
 
-if CONFIG["MOZ_BACKGROUNDTASKS"]:
-    DEFINES["MOZ_BACKGROUNDTASKS"] = True
-
 REQUIRES_UNIFIED_BUILD = True
diff --git a/netwerk/cache2/moz.build b/netwerk/cache2/moz.build
index e2de180eaede..9d999597e3d4 100644
--- a/netwerk/cache2/moz.build
+++ b/netwerk/cache2/moz.build
@@ -68,4 +68,3 @@ if CONFIG["MOZ_BACKGROUNDTASKS"]:
     EXTRA_JS_MODULES.backgroundtasks += [
         "BackgroundTask_purgeHTTPCache.sys.mjs",
     ]
-    DEFINES["MOZ_BACKGROUNDTASKS"] = True
diff --git a/startupcache/moz.build b/startupcache/moz.build
index c7f189ec2d8b..4ee94be455ee 100644
--- a/startupcache/moz.build
+++ b/startupcache/moz.build
@@ -31,9 +31,6 @@ XPIDL_SOURCES += [
     "nsIStartupCacheInfo.idl",
 ]
 
-if CONFIG["MOZ_BACKGROUNDTASKS"]:
-    DEFINES["MOZ_BACKGROUNDTASKS"] = True
-
 FINAL_LIBRARY = "xul"
 
 REQUIRES_UNIFIED_BUILD = True
diff --git a/toolkit/components/telemetry/moz.build b/toolkit/components/telemetry/moz.build
index 0a7e5b59d1fd..078d789340ae 100644
--- a/toolkit/components/telemetry/moz.build
+++ b/toolkit/components/telemetry/moz.build
@@ -19,10 +19,6 @@ if CONFIG["COMPILE_ENVIRONMENT"]:
 
 DEFINES["MOZ_APP_VERSION"] = '"%s"' % CONFIG["MOZ_APP_VERSION"]
 
-for var in ("MOZ_BACKGROUNDTASKS",):
-    if CONFIG[var]:
-        DEFINES[var] = True
-
 LOCAL_INCLUDES += [
     "/xpcom/build",
     "/xpcom/threads",
diff --git a/toolkit/modules/moz.build b/toolkit/modules/moz.build
index 17dee611f315..21d5b07b3f89 100644
--- a/toolkit/modules/moz.build
+++ b/toolkit/modules/moz.build
@@ -286,7 +286,6 @@ for var in (
 
 for var in (
     "MOZ_ALLOW_ADDON_SIDELOAD",
-    "MOZ_BACKGROUNDTASKS",
     "MOZ_SYSTEM_NSS",
     "MOZ_SYSTEM_POLICIES",
     "MOZ_UNSIGNED_APP_SCOPE",
diff --git a/toolkit/moz.configure b/toolkit/moz.configure
index 8a73289bbf7e..6b7e181879c4 100644
--- a/toolkit/moz.configure
+++ b/toolkit/moz.configure
@@ -2656,9 +2656,13 @@ option(
 )
 
 
-set_config(
-    "MOZ_BACKGROUNDTASKS", depends_if("--enable-backgroundtasks")(lambda _: True)
-)
+@depends("--enable-backgroundtasks")
+def background_tasks(value):
+    return bool(value)
+
+
+set_config("MOZ_BACKGROUNDTASKS", background_tasks)
+set_define("MOZ_BACKGROUNDTASKS", background_tasks)
 
 
 # Update-related programs: updater, maintenance service, update agent,
diff --git a/toolkit/mozapps/update/updater/updater-common.build b/toolkit/mozapps/update/updater/updater-common.build
index 7c58d374bbc2..16c2d1500392 100644
--- a/toolkit/mozapps/update/updater/updater-common.build
+++ b/toolkit/mozapps/update/updater/updater-common.build
@@ -92,7 +92,7 @@ if CONFIG["MOZ_TSAN"]:
 DEFINES["SPRINTF_H_USES_VSNPRINTF"] = True
 DEFINES["NS_NO_XPCOM"] = True
 DisableStlWrapping()
-for var in ("MAR_CHANNEL_ID", "MOZ_APP_VERSION", "MOZ_BACKGROUNDTASKS"):
+for var in ("MAR_CHANNEL_ID", "MOZ_APP_VERSION"):
     DEFINES[var] = '"%s"' % CONFIG[var]
 
 LOCAL_INCLUDES += [
diff --git a/toolkit/profile/moz.build b/toolkit/profile/moz.build
index 2581f4b5eb5f..5eb7a3053d5d 100644
--- a/toolkit/profile/moz.build
+++ b/toolkit/profile/moz.build
@@ -28,9 +28,6 @@ if CONFIG["OS_ARCH"] == "WINNT":
 if CONFIG["OS_TARGET"] == "Android":
     UNIFIED_SOURCES += ["ProfileUnlockerAndroid.cpp"]
 
-if CONFIG["MOZ_BACKGROUNDTASKS"]:
-    DEFINES["MOZ_BACKGROUNDTASKS"] = True
-
 UNIFIED_SOURCES += ["nsToolkitProfileService.cpp"]
 
 LOCAL_INCLUDES += [
diff --git a/toolkit/xre/moz.build b/toolkit/xre/moz.build
index a3ea40edf0a3..970c10d243b8 100644
--- a/toolkit/xre/moz.build
+++ b/toolkit/xre/moz.build
@@ -288,7 +288,4 @@ FINAL_TARGET_PP_FILES += ["platform.ini"]
 if CONFIG["ENABLE_TESTS"]:
     DIRS += ["test/gtest"]
 
-if CONFIG["MOZ_BACKGROUNDTASKS"]:
-    DEFINES["MOZ_BACKGROUNDTASKS"] = True
-
 REQUIRES_UNIFIED_BUILD = True
diff --git a/widget/windows/moz.build b/widget/windows/moz.build
index eb3ad2db2280..ac2000d0939f 100644
--- a/widget/windows/moz.build
+++ b/widget/windows/moz.build
@@ -182,7 +182,7 @@ DEFINES["MOZ_APP_NAME"] = '"%s"' % CONFIG["MOZ_APP_NAME"]
 # Turn `firefox` into `Firefox`.
 DEFINES["MOZ_TOAST_APP_NAME"] = '"%s"' % CONFIG["MOZ_APP_NAME"].title()
 
-for var in ("MOZ_ENABLE_D3D10_LAYER", "MOZ_BACKGROUNDTASKS"):
+for var in ("MOZ_ENABLE_D3D10_LAYER",):
     if CONFIG[var]:
         DEFINES[var] = True
 
diff --git a/xpcom/base/moz.build b/xpcom/base/moz.build
index e0ec7fd20ab0..5bcedee909c0 100644
--- a/xpcom/base/moz.build
+++ b/xpcom/base/moz.build
@@ -257,6 +257,3 @@ LOCAL_INCLUDES += [
 
 if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
     CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
-
-if CONFIG["MOZ_BACKGROUNDTASKS"]:
-    DEFINES["MOZ_BACKGROUNDTASKS"] = True
diff --git a/xpcom/components/moz.build b/xpcom/components/moz.build
index 779b75dbc495..95ee64e985ac 100644
--- a/xpcom/components/moz.build
+++ b/xpcom/components/moz.build
@@ -78,9 +78,6 @@ if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
     if CONFIG["MOZ_ENABLE_DBUS"]:
         CXXFLAGS += CONFIG["MOZ_DBUS_GLIB_CFLAGS"]
 
-if CONFIG["MOZ_BACKGROUNDTASKS"]:
-    DEFINES["MOZ_BACKGROUNDTASKS"] = True
-
 include("/ipc/chromium/chromium-config.mozbuild")
 
 PYTHON_UNITTEST_MANIFESTS += [