diff --git a/pkgs/servers/sql/postgresql/ext/pgvecto-rs/0002-std-detect-use-upstream.diff b/pkgs/servers/sql/postgresql/ext/pgvecto-rs/0002-std-detect-use-upstream.diff
new file mode 100644
index 0000000000000..bd20cf6619a71
--- /dev/null
+++ b/pkgs/servers/sql/postgresql/ext/pgvecto-rs/0002-std-detect-use-upstream.diff
@@ -0,0 +1,25 @@
+diff --git a/Cargo.lock b/Cargo.lock
+index a52b978..092bc1d 100644
+--- a/Cargo.lock
++++ b/Cargo.lock
+@@ -2788,7 +2788,7 @@ checksum = "a8f112729512f8e442d81f95a8a7ddf2b7c6b8a1a6f509a95864142b30cab2d3"
+ [[package]]
+ name = "std_detect"
+ version = "0.1.5"
+-source = "git+https://github.com/tensorchord/stdarch.git?branch=avx512fp16#db0cdbc9b02074bfddabfd23a4a681f21640eada"
++source = "git+https://github.com/rust-lang/stdarch.git?branch=master#d2b1a070afc72d9ba4df80e055109ede5fc0a81f"
+ dependencies = [
+  "cfg-if",
+  "libc",
+diff --git a/crates/detect/Cargo.toml b/crates/detect/Cargo.toml
+index b3ac782..c671c6a 100644
+--- a/crates/detect/Cargo.toml
++++ b/crates/detect/Cargo.toml
+@@ -4,6 +4,6 @@ version.workspace = true
+ edition.workspace = true
+ 
+ [dependencies]
+-std_detect = { git = "https://github.com/tensorchord/stdarch.git", branch = "avx512fp16" }
++std_detect = { git = "https://github.com/rust-lang/stdarch.git", branch = "master" }
+ ctor = "0.2.6"
+ rustix.workspace = true
diff --git a/pkgs/servers/sql/postgresql/ext/pgvecto-rs/Cargo.lock b/pkgs/servers/sql/postgresql/ext/pgvecto-rs/Cargo.lock
index a52b9787460e5..092bc1d2e31c8 100644
--- a/pkgs/servers/sql/postgresql/ext/pgvecto-rs/Cargo.lock
+++ b/pkgs/servers/sql/postgresql/ext/pgvecto-rs/Cargo.lock
@@ -2788,7 +2788,7 @@ checksum = "a8f112729512f8e442d81f95a8a7ddf2b7c6b8a1a6f509a95864142b30cab2d3"
 [[package]]
 name = "std_detect"
 version = "0.1.5"
-source = "git+https://github.com/tensorchord/stdarch.git?branch=avx512fp16#db0cdbc9b02074bfddabfd23a4a681f21640eada"
+source = "git+https://github.com/rust-lang/stdarch.git?branch=master#d2b1a070afc72d9ba4df80e055109ede5fc0a81f"
 dependencies = [
  "cfg-if",
  "libc",
diff --git a/pkgs/servers/sql/postgresql/ext/pgvecto-rs/default.nix b/pkgs/servers/sql/postgresql/ext/pgvecto-rs/default.nix
index 9cbf6ae442e4e..0041c555362bf 100644
--- a/pkgs/servers/sql/postgresql/ext/pgvecto-rs/default.nix
+++ b/pkgs/servers/sql/postgresql/ext/pgvecto-rs/default.nix
@@ -44,6 +44,10 @@ in
       src = ./0001-read-clang-flags-from-environment.diff;
       clang = lib.getExe clang;
     })
+    # Fix build failure on rustc 1.78 due to missing feature flag.
+    # Can (likely) be removed when pgvecto-rs 0.3.0 is released.
+    # See https://github.com/NixOS/nixpkgs/issues/320131
+    ./0002-std-detect-use-upstream.diff
   ];
 
   src = fetchFromGitHub {
@@ -59,7 +63,7 @@ in
     lockFile = ./Cargo.lock;
     outputHashes = {
       "openai_api_rust-0.1.8" = "sha256-os5Y8KIWXJEYEcNzzT57wFPpEXdZ2Uy9W3j5+hJhhR4=";
-      "std_detect-0.1.5" = "sha256-RwWejfqyGOaeU9zWM4fbb/hiO1wMpxYPKEjLO0rtRmU=";
+      "std_detect-0.1.5" = "sha256-Rsy8N0pTJ/3AIHjRyeOeyY7Q9Ho46ZcDmJFurCbRxiQ=";
     };
   };