--- a/browser/config/mozconfigs/linux64/debug
+++ b/browser/config/mozconfigs/linux64/debug
@@ -13,11 +13,11 @@ export MOZILLA_OFFICIAL=1
 # Treat warnings as errors (modulo ALLOW_COMPILER_WARNINGS).
 ac_add_options --enable-warnings-as-errors
 
 # Package js shell.
 export MOZ_PACKAGE_JSSHELL=1
 
 ac_add_options --with-branding=browser/branding/nightly
 
-. "$topsrcdir/build/unix/mozconfig.rust"
+. "$topsrcdir/build/mozconfig.rust"
 . "$topsrcdir/build/mozconfig.common.override"
 . "$topsrcdir/build/mozconfig.cache"

--- a/browser/config/mozconfigs/linux64/nightly
+++ b/browser/config/mozconfigs/linux64/nightly
@@ -5,11 +5,11 @@ ac_add_options --enable-verify-mar
 
 # This will overwrite the default of stripping everything and keep the symbol table.
 # This is useful for profiling and debugging and only increases the package size
 # by 2 MBs.
 STRIP_FLAGS="--strip-debug"
 
 ac_add_options --with-branding=browser/branding/nightly
 
-. "$topsrcdir/build/unix/mozconfig.rust"
+. "$topsrcdir/build/mozconfig.rust"
 . "$topsrcdir/build/mozconfig.common.override"
 . "$topsrcdir/build/mozconfig.cache"

--- a/browser/config/mozconfigs/whitelist
+++ b/browser/config/mozconfigs/whitelist
@@ -35,17 +35,17 @@ whitelist['nightly']['linux32'] += [
 
 whitelist['nightly']['linux64'] += [
     'export MOZILLA_OFFICIAL=1',
     'export MOZ_TELEMETRY_REPORTING=1',
     "mk_add_options PROFILE_GEN_SCRIPT='$(PYTHON) @MOZ_OBJDIR@/_profile/pgo/profileserver.py 10'",
     'STRIP_FLAGS="--strip-debug"',
     'ac_add_options --with-ccache=/usr/bin/ccache',
     '. "$topsrcdir/build/mozconfig.cache"',
-    '. "$topsrcdir/build/unix/mozconfig.rust"',
+    '. "$topsrcdir/build/mozconfig.rust"',
 ]
 
 whitelist['nightly']['macosx-universal'] += [
     'if test "${MOZ_UPDATE_CHANNEL}" = "nightly"; then',
     'ac_add_options --with-macbundlename-prefix=Firefox',
     'fi',
     'mk_add_options MOZ_MAKE_FLAGS="-j12"',
     'ac_add_options --with-ccache',

new file mode 100644
--- /dev/null
+++ b/build/mozconfig.rust
@@ -0,0 +1,9 @@
+# Options to enable rust in automation builds.
+
+# Tell configure to use the tooltool rustc.
+# Assume this is compiled with --enable-rpath so we don't
+# have to set LD_LIBRARY_PATH.
+RUSTC="$topsrcdir/rustc/bin/rustc"
+
+# Enable rust in the build.
+ac_add_options --enable-rust

deleted file mode 100644
--- a/build/unix/mozconfig.rust
+++ /dev/null
@@ -1,9 +0,0 @@
-# Options to enable rust in automation builds.
-
-# Tell configure to use the tooltool rustc.
-# Assume this is compiled with --enable-rpath so we don't
-# have to set LD_LIBRARY_PATH.
-RUSTC="$topsrcdir/rustc/bin/rustc"
-
-# Enable rust in the build.
-ac_add_options --enable-rust