diff --git a/build/moz.configure/lto-pgo.configure b/build/moz.configure/lto-pgo.configure
index 7db7b66f140a..c4436d24db36 100644
--- a/build/moz.configure/lto-pgo.configure
+++ b/build/moz.configure/lto-pgo.configure
@@ -264,6 +264,6 @@ set_config('MOZ_LTO', lto.enabled)
 set_define('MOZ_LTO', lto.enabled)
 set_config('MOZ_LTO_CFLAGS', lto.cflags)
 set_config('MOZ_LTO_LDFLAGS', lto.ldflags)
-set_config('MOZ_LTO_RUST', lto.rust_lto)
+set_config('MOZ_LTO_RUST_CROSS', lto.rust_lto)
 add_old_configure_assignment('MOZ_LTO_CFLAGS', lto.cflags)
 add_old_configure_assignment('MOZ_LTO_LDFLAGS', lto.ldflags)
diff --git a/config/makefiles/rust.mk b/config/makefiles/rust.mk
index 584319b6d572..a5d451b0dc1b 100644
--- a/config/makefiles/rust.mk
+++ b/config/makefiles/rust.mk
@@ -59,7 +59,8 @@ cargo_rustc_flags = $(CARGO_RUSTCFLAGS)
 ifndef DEVELOPER_OPTIONS
 ifndef MOZ_DEBUG_RUST
 # Enable link-time optimization for release builds, but not when linking
-# gkrust_gtest.
+# gkrust_gtest. And not when doing cross-language LTO.
+ifndef MOZ_LTO_RUST_CROSS
 ifeq (,$(findstring gkrust_gtest,$(RUST_LIBRARY_FILE)))
 cargo_rustc_flags += -Clto
 endif
@@ -70,6 +71,7 @@ RUSTFLAGS += -Cembed-bitcode=yes
 endif
 endif
 endif
+endif
 
 ifdef CARGO_INCREMENTAL
 export CARGO_INCREMENTAL
@@ -194,7 +196,7 @@ ifdef MOZ_PGO_RUST
 rust_pgo_flags := $(if $(MOZ_PROFILE_GENERATE),-C profile-generate=$(topobjdir)) $(if $(MOZ_PROFILE_USE),-C profile-use=$(PGO_PROFILE_PATH))
 endif
 
-$(target_rust_ltoable): RUSTFLAGS:=$(rustflags_override) $(rustflags_sancov) $(RUSTFLAGS) $(if $(MOZ_LTO_RUST),-Clinker-plugin-lto) $(rust_pgo_flags)
+$(target_rust_ltoable): RUSTFLAGS:=$(rustflags_override) $(rustflags_sancov) $(RUSTFLAGS) $(if $(MOZ_LTO_RUST_CROSS),-Clinker-plugin-lto) $(rust_pgo_flags)
 $(target_rust_nonltoable): RUSTFLAGS:=$(rustflags_override) $(rustflags_sancov) $(RUSTFLAGS)
 
 TARGET_RECIPES := $(target_rust_ltoable) $(target_rust_nonltoable)
@@ -306,12 +308,12 @@ $(RUST_LIBRARY_FILE): force-cargo-library-build
 # When we are building in --enable-release mode; we add an additional check to confirm
 # that we are not importing any networking-related functions in rust code. This reduces
 # the chance of proxy bypasses originating from rust code.
-# The check only works when rust code is built with -Clto but without MOZ_LTO_RUST.
+# The check only works when rust code is built with -Clto but without MOZ_LTO_RUST_CROSS.
 # Sanitizers and sancov also fail because compiler-rt hooks network functions.
 ifndef MOZ_PROFILE_GENERATE
 ifeq ($(OS_ARCH), Linux)
 ifeq (,$(rustflags_sancov)$(MOZ_ASAN)$(MOZ_TSAN)$(MOZ_UBSAN))
-ifndef MOZ_LTO_RUST
+ifndef MOZ_LTO_RUST_CROSS
 ifneq (,$(filter -Clto,$(cargo_rustc_flags)))
 	$(call py_action,check_binary,--target --networking $@)
 endif