diff --git a/wasmtime-wasi/sandboxed-system-primitives/include/wasmtime_ssp.h b/wasmtime-wasi/sandboxed-system-primitives/include/wasmtime_ssp.h
index 49af8252508b..086a63a36743 100644
--- a/wasmtime-wasi/sandboxed-system-primitives/include/wasmtime_ssp.h
+++ b/wasmtime-wasi/sandboxed-system-primitives/include/wasmtime_ssp.h
@@ -454,22 +454,6 @@ _Static_assert(_Alignof(__wasi_subscription_t) == 8, "non-wasi data layout");
 #define WASMTIME_SSP_SYSCALL_NAME(name)
 #endif
 
-__wasi_errno_t wasmtime_ssp_args_get(
-#if !defined(WASMTIME_SSP_STATIC_CURFDS)
-    struct argv_environ_values *arg_environ,
-#endif
-    char **argv,
-    char *argv_buf
-) WASMTIME_SSP_SYSCALL_NAME(args_get) __attribute__((__warn_unused_result__));
-
-__wasi_errno_t wasmtime_ssp_args_sizes_get(
-#if !defined(WASMTIME_SSP_STATIC_CURFDS)
-    struct argv_environ_values *arg_environ,
-#endif
-    size_t *argc,
-    size_t *argv_buf_size
-) WASMTIME_SSP_SYSCALL_NAME(args_sizes_get) __attribute__((__warn_unused_result__));
-
 __wasi_errno_t wasmtime_ssp_clock_res_get(
     __wasi_clockid_t clock_id,
     __wasi_timestamp_t *resolution
@@ -481,22 +465,6 @@ __wasi_errno_t wasmtime_ssp_clock_time_get(
     __wasi_timestamp_t *time
 ) WASMTIME_SSP_SYSCALL_NAME(clock_time_get) __attribute__((__warn_unused_result__));
 
-__wasi_errno_t wasmtime_ssp_environ_get(
-#if !defined(WASMTIME_SSP_STATIC_CURFDS)
-    struct argv_environ_values *arg_environ,
-#endif
-    char **environ,
-    char *environ_buf
-) WASMTIME_SSP_SYSCALL_NAME(environ_get) __attribute__((__warn_unused_result__));
-
-__wasi_errno_t wasmtime_ssp_environ_sizes_get(
-#if !defined(WASMTIME_SSP_STATIC_CURFDS)
-    struct argv_environ_values *arg_environ,
-#endif
-    size_t *environ_count,
-    size_t *environ_buf_size
-) WASMTIME_SSP_SYSCALL_NAME(environ_sizes_get) __attribute__((__warn_unused_result__));
-
 __wasi_errno_t wasmtime_ssp_fd_prestat_get(
 #if !defined(WASMTIME_SSP_STATIC_CURFDS)
     struct fd_prestats *prestats,
diff --git a/wasmtime-wasi/sandboxed-system-primitives/src/posix.c b/wasmtime-wasi/sandboxed-system-primitives/src/posix.c
index 11e88fbec514..f836779fdb03 100644
--- a/wasmtime-wasi/sandboxed-system-primitives/src/posix.c
+++ b/wasmtime-wasi/sandboxed-system-primitives/src/posix.c
@@ -2690,48 +2690,6 @@ __wasi_errno_t wasmtime_ssp_sched_yield(void) {
   return 0;
 }
 
-__wasi_errno_t wasmtime_ssp_args_get(
-#if !defined(WASMTIME_SSP_STATIC_CURFDS)
-  struct argv_environ_values *argv_environ,
-#endif
-  char **argv,
-  char *argv_buf
-) {
-  for (size_t i = 0; i < argv_environ->argc; ++i) {
-    argv[i] = argv_buf + (argv_environ->argv[i] - argv_environ->argv_buf);
-  }
-  argv[argv_environ->argc] = NULL;
-  memcpy(argv_buf, argv_environ->argv_buf, argv_environ->argv_buf_size);
-  return __WASI_ESUCCESS;
-}
-
-__wasi_errno_t wasmtime_ssp_args_sizes_get(
-#if !defined(WASMTIME_SSP_STATIC_CURFDS)
-  struct argv_environ_values *argv_environ,
-#endif
-  size_t *argc,
-  size_t *argv_buf_size
-) {
-  *argc = argv_environ->argc;
-  *argv_buf_size = argv_environ->argv_buf_size;
-  return __WASI_ESUCCESS;
-}
-
-__wasi_errno_t wasmtime_ssp_environ_get(
-#if !defined(WASMTIME_SSP_STATIC_CURFDS)
-  struct argv_environ_values *argv_environ,
-#endif
-  char **environ,
-  char *environ_buf
-) {
-  for (size_t i = 0; i < argv_environ->environ_count; ++i) {
-    environ[i] = environ_buf + (argv_environ->environ[i] - argv_environ->environ_buf);
-  }
-  environ[argv_environ->environ_count] = NULL;
-  memcpy(environ_buf, argv_environ->environ_buf, argv_environ->environ_buf_size);
-  return __WASI_ESUCCESS;
-}
-
 __wasi_errno_t wasmtime_ssp_environ_sizes_get(
 #if !defined(WASMTIME_SSP_STATIC_CURFDS)
   struct argv_environ_values *argv_environ,
diff --git a/wasmtime-wasi/src/host_impls.rs b/wasmtime-wasi/src/host_impls.rs
index 8383a41372b7..e3824839b250 100644
--- a/wasmtime-wasi/src/host_impls.rs
+++ b/wasmtime-wasi/src/host_impls.rs
@@ -1,5 +1,65 @@
+use super::host;
 use super::wasm32;
 
+pub unsafe fn wasmtime_ssp_args_get(
+    argv_environ: &mut host::argv_environ_values,
+    argv: &mut [*mut host::char],
+    argv_buf: *mut host::char,
+) -> wasm32::__wasi_errno_t {
+    for i in 0..(*argv_environ).argc {
+        let buf_off = isize::checked_sub(
+            *(*argv_environ).argv.offset(i as isize) as _,
+            (*argv_environ).argv_buf as _,
+        )
+        .expect("argv[i] - argv_buf overflows");
+        argv[i] = argv_buf.offset(buf_off);
+    }
+    argv[(*argv_environ).argc] = std::ptr::null_mut();
+    argv_buf.copy_from((*argv_environ).argv_buf, (*argv_environ).argv_buf_size);
+    wasm32::__WASI_ESUCCESS
+}
+
+pub fn wasmtime_ssp_args_sizes_get(
+    argv_environ: &mut host::argv_environ_values,
+    argc: &mut usize,
+    argv_buf_size: &mut usize,
+) -> wasm32::__wasi_errno_t {
+    *argc = (*argv_environ).argc;
+    *argv_buf_size = (*argv_environ).argv_buf_size;
+    wasm32::__WASI_ESUCCESS
+}
+
+pub unsafe fn wasmtime_ssp_environ_get(
+    argv_environ: &mut host::argv_environ_values,
+    environ: &mut [*mut host::char],
+    environ_buf: *mut host::char,
+) -> wasm32::__wasi_errno_t {
+    for i in 0..(*argv_environ).environ_count {
+        let buf_off = isize::checked_sub(
+            *(*argv_environ).environ.offset(i as isize) as _,
+            (*argv_environ).environ_buf as _,
+        )
+        .expect("environ[i] - environ_buf overflows");
+        environ[i] = environ_buf.offset(buf_off);
+    }
+    environ[(*argv_environ).environ_count] = std::ptr::null_mut();
+    environ_buf.copy_from(
+        (*argv_environ).environ_buf,
+        (*argv_environ).environ_buf_size,
+    );
+    wasm32::__WASI_ESUCCESS
+}
+
+pub fn wasmtime_ssp_environ_sizes_get(
+    argv_environ: &mut host::argv_environ_values,
+    environ_count: &mut usize,
+    environ_buf_size: &mut usize,
+) -> wasm32::__wasi_errno_t {
+    *environ_count = (*argv_environ).environ_count;
+    *environ_buf_size = (*argv_environ).environ_buf_size;
+    wasm32::__WASI_ESUCCESS
+}
+
 pub fn wasmtime_ssp_proc_exit(rval: wasm32::__wasi_exitcode_t) {
     ::std::process::exit(rval as i32)
 }
diff --git a/wasmtime-wasi/src/syscalls.rs b/wasmtime-wasi/src/syscalls.rs
index 7901f5531a76..5f8141967fda 100644
--- a/wasmtime-wasi/src/syscalls.rs
+++ b/wasmtime-wasi/src/syscalls.rs
@@ -192,7 +192,7 @@ syscalls! {
         let mut host_argv = Vec::new();
         host_argv.resize((*argv_environ).argc + 1, ptr::null_mut());
 
-        let e = host::wasmtime_ssp_args_get(argv_environ, host_argv.as_mut_ptr(), host_argv_buf);
+        let e = host_impls::wasmtime_ssp_args_get(&mut *argv_environ, host_argv.as_mut_slice(), host_argv_buf);
 
         encode_charstar_slice(argv, host_argv, argv_buf, host_argv_buf);
 
@@ -223,7 +223,7 @@ syscalls! {
         let vmctx = &mut *vmctx;
         let argv_environ = get_argv_environ(vmctx);
 
-        let e = host::wasmtime_ssp_args_sizes_get(argv_environ, &mut host_argc, &mut host_argv_buf_size);
+        let e = host_impls::wasmtime_ssp_args_sizes_get(&mut *argv_environ, &mut host_argc, &mut host_argv_buf_size);
 
         trace!("     | *argc={:?}", host_argc);
         encode_usize_byref(vmctx, argc, host_argc);
@@ -323,7 +323,7 @@ syscalls! {
         let mut host_environ = Vec::new();
         host_environ.resize((*argv_environ).environ_count + 1, ptr::null_mut());
 
-        let e = host::wasmtime_ssp_environ_get(argv_environ, host_environ.as_mut_ptr(), host_environ_buf);
+        let e = host_impls::wasmtime_ssp_environ_get(&mut *argv_environ, host_environ.as_mut_slice(), host_environ_buf);
 
         encode_charstar_slice(environ, host_environ, environ_buf, host_environ_buf);
 
@@ -354,7 +354,7 @@ syscalls! {
         let vmctx = &mut *vmctx;
         let argv_environ = get_argv_environ(vmctx);
 
-        let e = host::wasmtime_ssp_environ_sizes_get(argv_environ, &mut host_environ_count, &mut host_environ_buf_size);
+        let e = host_impls::wasmtime_ssp_environ_sizes_get(&mut *argv_environ, &mut host_environ_count, &mut host_environ_buf_size);
 
         trace!("     | *environ_count={:?}", host_environ_count);
         encode_usize_byref(vmctx, environ_count, host_environ_count);