diff --git a/build/trivalent.spec b/build/trivalent.spec
index f8ad9584..5a9a5e10 100644
--- a/build/trivalent.spec
+++ b/build/trivalent.spec
@@ -524,7 +524,6 @@ CHROMIUM_GN_DEFINES+=" clang_use_chrome_plugins=false"
 CHROMIUM_GN_DEFINES+=" rust_sysroot_absolute=\"$(rustc --print sysroot)\""
 CHROMIUM_GN_DEFINES+=" rust_bindgen_root=\"$rust_bindgen_root\""
 CHROMIUM_GN_DEFINES+=" rustc_version=\"$(rustc --version)\""
-CHROMIUM_GN_DEFINES+=" rustc_nightly_capability=true"
 CHROMIUM_GN_DEFINES+=" chrome_pgo_phase=0"
 %endif
 CHROMIUM_GN_DEFINES+=' system_libdir="%{_lib}"'
diff --git a/chromium_patches/0003-Assume-rustc-is-nightly-if-building-Chromium.patch b/chromium_patches/0003-Assume-rustc-is-nightly-if-building-Chromium.patch
new file mode 100644
index 00000000..cab4c7b6
--- /dev/null
+++ b/chromium_patches/0003-Assume-rustc-is-nightly-if-building-Chromium.patch
@@ -0,0 +1,36 @@
+From 272bb673e5a2665321b7a62cbf75f58e60130c5d Mon Sep 17 00:00:00 2001
+From: LN Liberda <lauren@selfisekai.rocks>
+Date: Tue, 20 Jan 2026 13:00:55 -0800
+Subject: [PATCH] Assume rustc is nightly if building Chromium
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Nightly is required to build full Chromium.
+This variable was introduced to build just V8 with ancient Rust,
+and is mostly used to bring incompatibilities with current Rust versions.
+
+Bug: none
+Change-Id: Ie652a7af8414aac5d7dc7cf9f1c27f04b5ed1034
+Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7492958
+Commit-Queue: Łukasz Anforowicz <lukasza@chromium.org>
+Reviewed-by: Daniel Cheng <dcheng@chromium.org>
+Reviewed-by: Łukasz Anforowicz <lukasza@chromium.org>
+Cr-Commit-Position: refs/heads/main@{#1571838}
+---
+ build/config/rust.gni | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/build/config/rust.gni b/build/config/rust.gni
+index 36a1fdd350f4ac..f88d57f45996cb 100644
+--- a/build/config/rust.gni
++++ b/build/config/rust.gni
+@@ -121,7 +121,7 @@ use_chromium_rust_toolchain = rust_sysroot_absolute == ""
+ # `rustc_nightly_capability = false` will make the build avoid the use of
+ # Rust nightly features. There are no bots that test this and there is no
+ # guarantee it will work, but we accept patches for this configuration.
+-rustc_nightly_capability = use_chromium_rust_toolchain
++rustc_nightly_capability = use_chromium_rust_toolchain || build_with_chromium
+ 
+ # Platform support for the Rust toolchain.
+ chromium_toolchain_supports_platform = !is_wasm