diff --git a/arch/arm/rust/target.json b/arch/arm/rust/target.json
index 37710eb727b1ce..3f845b8221dcd1 100644
--- a/arch/arm/rust/target.json
+++ b/arch/arm/rust/target.json
@@ -9,7 +9,6 @@
   "function-sections": false,
   "has-elf-tls": true,
   "has-rpath": true,
-  "is-builtin": true,
   "linker-is-gnu": true,
   "llvm-target": "arm-unknown-linux-gnueabi",
   "max-atomic-width": 64,
diff --git a/arch/arm64/rust/target.json b/arch/arm64/rust/target.json
index 9ea86ed6c736c2..a1e06513c1d3ef 100644
--- a/arch/arm64/rust/target.json
+++ b/arch/arm64/rust/target.json
@@ -7,7 +7,6 @@
   "env": "gnu",
   "features": "+strict-align,+neon,+fp-armv8",
   "function-sections": false,
-  "is-builtin": true,
   "linker-flavor": "gcc",
   "linker-is-gnu": true,
   "llvm-target": "aarch64-unknown-none",
diff --git a/arch/powerpc/rust/target.json b/arch/powerpc/rust/target.json
index 1e53f83080927c..b7c5ec469222d3 100644
--- a/arch/powerpc/rust/target.json
+++ b/arch/powerpc/rust/target.json
@@ -6,7 +6,6 @@
   "env": "gnu",
   "features": "-altivec,-vsx,-hard-float",
   "function-sections": false,
-  "is-builtin": true,
   "linker-flavor": "gcc",
   "linker-is-gnu": true,
   "llvm-target": "powerpc64le-elf",
diff --git a/arch/riscv/rust/rv32ima.json b/arch/riscv/rust/rv32ima.json
index 8e9b46011e7c98..4a79f2a13b8b47 100644
--- a/arch/riscv/rust/rv32ima.json
+++ b/arch/riscv/rust/rv32ima.json
@@ -9,7 +9,6 @@
   "env": "gnu",
   "features": "+m,+a",
   "function-sections": false,
-  "is-builtin": true,
   "linker-flavor": "gcc",
   "linker-is-gnu": true,
   "llvm-target": "riscv32",
diff --git a/arch/riscv/rust/rv32imac.json b/arch/riscv/rust/rv32imac.json
index 2b3a139da999f4..fd833b5c37ceab 100644
--- a/arch/riscv/rust/rv32imac.json
+++ b/arch/riscv/rust/rv32imac.json
@@ -9,7 +9,6 @@
   "env": "gnu",
   "features": "+m,+a,+c",
   "function-sections": false,
-  "is-builtin": true,
   "linker-flavor": "gcc",
   "linker-is-gnu": true,
   "llvm-target": "riscv32",
diff --git a/arch/riscv/rust/rv64ima.json b/arch/riscv/rust/rv64ima.json
index 091da50069a31b..d55adb6377b51f 100644
--- a/arch/riscv/rust/rv64ima.json
+++ b/arch/riscv/rust/rv64ima.json
@@ -9,7 +9,6 @@
   "env": "gnu",
   "features": "+m,+a",
   "function-sections": false,
-  "is-builtin": true,
   "linker-flavor": "gcc",
   "linker-is-gnu": true,
   "llvm-target": "riscv64",
diff --git a/arch/riscv/rust/rv64imac.json b/arch/riscv/rust/rv64imac.json
index aa5a8f4549f1e6..644ba9fd2be12d 100644
--- a/arch/riscv/rust/rv64imac.json
+++ b/arch/riscv/rust/rv64imac.json
@@ -9,7 +9,6 @@
   "env": "gnu",
   "features": "+m,+a,+c",
   "function-sections": false,
-  "is-builtin": true,
   "linker-flavor": "gcc",
   "linker-is-gnu": true,
   "llvm-target": "riscv64",
diff --git a/arch/x86/rust/target.json b/arch/x86/rust/target.json
index 76ac800d38efb2..f2f4af5db35e70 100644
--- a/arch/x86/rust/target.json
+++ b/arch/x86/rust/target.json
@@ -9,7 +9,6 @@
   "env": "gnu",
   "features": "-mmx,-sse,-sse2,-sse3,-ssse3,-sse4.1,-sse4.2,-3dnow,-3dnowa,-avx,-avx2,+soft-float",
   "function-sections": false,
-  "is-builtin": true,
   "linker-flavor": "gcc",
   "linker-is-gnu": true,
   "llvm-target": "x86_64-elf",