diff --git a/lib/std/os/linux/mips.zig b/lib/std/os/linux/mips.zig
index 8409aad1023c53a93f21fb87cd202ada89c3d227..c9c8fc71a65d6f93ad7aa77c4203c943e6df83fa 100644
--- a/lib/std/os/linux/mips.zig
+++ b/lib/std/os/linux/mips.zig
@@ -75,12 +75,15 @@ pub fn syscall4(
     arg3: syscall_arg_t,
     arg4: syscall_arg_t,
 ) u32 {
+    // $7 is both an input and a clobber.
+    var r7_out: syscall_arg_t = undefined;
     return asm volatile (
         \\ syscall
         \\ beq $a3, $zero, 1f
         \\ subu $v0, $zero, $v0
         \\1:
         : [ret] "={$2}" (-> u32),
+          [r7_out] "={$7}" (r7_out),
         : [number] "{$2}" (@backingInt(number)),
           [arg1] "{$4}" (arg1),
           [arg2] "{$5}" (arg2),
@@ -100,6 +103,8 @@ pub fn syscall5(
     arg4: syscall_arg_t,
     arg5: syscall_arg_t,
 ) u32 {
+    // $7 is both an input and a clobber.
+    var r7_out: syscall_arg_t = undefined;
     return asm volatile (
         \\ subu $sp, $sp, 24
         \\ sw %[arg5], 16($sp)
@@ -109,6 +114,7 @@ pub fn syscall5(
         \\ subu $v0, $zero, $v0
         \\1:
         : [ret] "={$2}" (-> u32),
+          [r7_out] "={$7}" (r7_out),
         : [number] "{$2}" (@backingInt(number)),
           [arg1] "{$4}" (arg1),
           [arg2] "{$5}" (arg2),
@@ -127,6 +133,8 @@ pub fn syscall6(
     arg5: syscall_arg_t,
     arg6: syscall_arg_t,
 ) u32 {
+    // $7 is both an input and a clobber.
+    var r7_out: syscall_arg_t = undefined;
     return asm volatile (
         \\ subu $sp, $sp, 24
         \\ sw %[arg5], 16($sp)
@@ -137,6 +145,7 @@ pub fn syscall6(
         \\ subu $v0, $zero, $v0
         \\1:
         : [ret] "={$2}" (-> u32),
+          [r7_out] "={$7}" (r7_out),
         : [number] "{$2}" (@backingInt(number)),
           [arg1] "{$4}" (arg1),
           [arg2] "{$5}" (arg2),
@@ -157,6 +166,8 @@ pub fn syscall7(
     arg6: syscall_arg_t,
     arg7: syscall_arg_t,
 ) u32 {
+    // $7 is both an input and a clobber.
+    var r7_out: syscall_arg_t = undefined;
     return asm volatile (
         \\ subu $sp, $sp, 32
         \\ sw %[arg5], 16($sp)
@@ -168,6 +179,7 @@ pub fn syscall7(
         \\ subu $v0, $zero, $v0
         \\1:
         : [ret] "={$2}" (-> u32),
+          [r7_out] "={$7}" (r7_out),
         : [number] "{$2}" (@backingInt(number)),
           [arg1] "{$4}" (arg1),
           [arg2] "{$5}" (arg2),
diff --git a/lib/std/os/linux/mips64.zig b/lib/std/os/linux/mips64.zig
index 50f65ef93136257e1c942c80719b0ef929adcef4..c744caf8e667701a6d8eb0813ce811693724d31e 100644
--- a/lib/std/os/linux/mips64.zig
+++ b/lib/std/os/linux/mips64.zig
@@ -75,12 +75,15 @@ pub fn syscall4(
     arg3: syscall_arg_t,
     arg4: syscall_arg_t,
 ) u64 {
+    // $7 is both an input and a clobber.
+    var r7_out: syscall_arg_t = undefined;
     return asm volatile (
         \\ syscall
         \\ beq $a3, $zero, 1f
         \\ dsubu $v0, $zero, $v0
         \\1:
         : [ret] "={$2}" (-> u64),
+          [r7_out] "={$7}" (r7_out),
         : [number] "{$2}" (@backingInt(number)),
           [arg1] "{$4}" (arg1),
           [arg2] "{$5}" (arg2),
@@ -97,12 +100,15 @@ pub fn syscall5(
     arg4: syscall_arg_t,
     arg5: syscall_arg_t,
 ) u64 {
+    // $7 is both an input and a clobber.
+    var r7_out: syscall_arg_t = undefined;
     return asm volatile (
         \\ syscall
         \\ beq $a3, $zero, 1f
         \\ dsubu $v0, $zero, $v0
         \\1:
         : [ret] "={$2}" (-> u64),
+          [r7_out] "={$7}" (r7_out),
         : [number] "{$2}" (@backingInt(number)),
           [arg1] "{$4}" (arg1),
           [arg2] "{$5}" (arg2),
@@ -121,12 +127,15 @@ pub fn syscall6(
     arg5: syscall_arg_t,
     arg6: syscall_arg_t,
 ) u64 {
+    // $7 is both an input and a clobber.
+    var r7_out: syscall_arg_t = undefined;
     return asm volatile (
         \\ syscall
         \\ beq $a3, $zero, 1f
         \\ dsubu $v0, $zero, $v0
         \\1:
         : [ret] "={$2}" (-> u64),
+          [r7_out] "={$7}" (r7_out),
         : [number] "{$2}" (@backingInt(number)),
           [arg1] "{$4}" (arg1),
           [arg2] "{$5}" (arg2),
diff --git a/lib/std/os/linux/mipsn32.zig b/lib/std/os/linux/mipsn32.zig
index 414f96230b9dad0b923208bf055f0be912b4aae1..b96a3e928e1bcb0f04d68db346db2ca37af37541 100644
--- a/lib/std/os/linux/mipsn32.zig
+++ b/lib/std/os/linux/mipsn32.zig
@@ -75,12 +75,15 @@ pub fn syscall4(
     arg3: syscall_arg_t,
     arg4: syscall_arg_t,
 ) u32 {
+    // $7 is both an input and a clobber.
+    var r7_out: syscall_arg_t = undefined;
     return asm volatile (
         \\ syscall
         \\ beq $a3, $zero, 1f
         \\ subu $v0, $zero, $v0
         \\1:
         : [ret] "={$2}" (-> u32),
+          [r7_out] "={$7}" (r7_out),
         : [number] "{$2}" (@backingInt(number)),
           [arg1] "{$4}" (arg1),
           [arg2] "{$5}" (arg2),
@@ -97,12 +100,15 @@ pub fn syscall5(
     arg4: syscall_arg_t,
     arg5: syscall_arg_t,
 ) u32 {
+    // $7 is both an input and a clobber.
+    var r7_out: syscall_arg_t = undefined;
     return asm volatile (
         \\ syscall
         \\ beq $a3, $zero, 1f
         \\ subu $v0, $zero, $v0
         \\1:
         : [ret] "={$2}" (-> u32),
+          [r7_out] "={$7}" (r7_out),
         : [number] "{$2}" (@backingInt(number)),
           [arg1] "{$4}" (arg1),
           [arg2] "{$5}" (arg2),
@@ -121,12 +127,15 @@ pub fn syscall6(
     arg5: syscall_arg_t,
     arg6: syscall_arg_t,
 ) u32 {
+    // $7 is both an input and a clobber.
+    var r7_out: syscall_arg_t = undefined;
     return asm volatile (
         \\ syscall
         \\ beq $a3, $zero, 1f
         \\ subu $v0, $zero, $v0
         \\1:
         : [ret] "={$2}" (-> u32),
+          [r7_out] "={$7}" (r7_out),
         : [number] "{$2}" (@backingInt(number)),
           [arg1] "{$4}" (arg1),
           [arg2] "{$5}" (arg2),