diff --git a/Cargo.lock b/Cargo.lock
index 18ac80db9..53f1b1d5f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1482,6 +1482,7 @@ dependencies = [
 name = "wasmer-wasi"
 version = "0.1.0"
 dependencies = [
+ "libc 0.2.50 (registry+https://github.com/rust-lang/crates.io-index)",
  "wasmer-runtime-core 0.2.1",
 ]
 
diff --git a/lib/wasi/Cargo.toml b/lib/wasi/Cargo.toml
index 17a2f14f4..3d2151d3e 100644
--- a/lib/wasi/Cargo.toml
+++ b/lib/wasi/Cargo.toml
@@ -5,4 +5,5 @@ authors = ["The Wasmer Engineering Team <engineering@wasmer.io>"]
 edition = "2018"
 
 [dependencies]
-wasmer-runtime-core = { path = "../runtime-core", version = "0.2.1" }
\ No newline at end of file
+wasmer-runtime-core = { path = "../runtime-core", version = "0.2.1" }
+libc = "0.2.50"
\ No newline at end of file
diff --git a/lib/wasi/src/syscalls/mod.rs b/lib/wasi/src/syscalls/mod.rs
index 0ccc7bd64..95d5f5240 100644
--- a/lib/wasi/src/syscalls/mod.rs
+++ b/lib/wasi/src/syscalls/mod.rs
@@ -108,7 +108,13 @@ pub fn clock_res_get(
     clock_id: __wasi_clockid_t,
     resolution: WasmPtr<__wasi_timestamp_t>,
 ) -> __wasi_errno_t {
-    platform_clock_res_get(ctx, clock_id, resolution)
+    let memory = ctx.memory(0);
+
+    if let Some(out_addr) = resolution.deref(memory) {
+        platform_clock_res_get(clock_id, out_addr)
+    } else {
+        __WASI_EFAULT
+    }
 }
 
 pub fn clock_time_get(
@@ -117,7 +123,13 @@ pub fn clock_time_get(
     precision: __wasi_timestamp_t,
     time: WasmPtr<__wasi_timestamp_t>,
 ) -> __wasi_errno_t {
-    platform_clock_time_get(ctx, clock_id, precision, time)
+    let memory = ctx.memory(0);
+
+    if let Some(out_addr) = time.deref(memory) {
+        platform_clock_time_get(clock_id, precision, out_addr)
+    } else {
+        __WASI_EFAULT
+    }
 }
 
 /// ### `environ_get()`
diff --git a/lib/wasi/src/syscalls/unix/linux.rs b/lib/wasi/src/syscalls/unix/linux.rs
index 78ee51c9a..e68d470fa 100644
--- a/lib/wasi/src/syscalls/unix/linux.rs
+++ b/lib/wasi/src/syscalls/unix/linux.rs
@@ -1,20 +1,54 @@
 use crate::syscalls::types::*;
-use crate::ptr::{Array, WasmPtr},
-use wasmer_runtime_core::{memory::Memory, vm::Ctx};
+use libc::{
+    clock_getres, clock_gettime, timespec, CLOCK_MONOTONIC, CLOCK_PROCESS_CPUTIME_ID,
+    CLOCK_REALTIME, CLOCK_THREAD_CPUTIME_ID,
+};
+use std::cell::Cell;
+use std::mem;
 
 pub fn platform_clock_res_get(
-    ctx: &mut Ctx,
     clock_id: __wasi_clockid_t,
-    resolution: WasmPtr<__wasi_timestamp_t>,
+    resolution: &Cell<__wasi_timestamp_t>,
 ) -> __wasi_errno_t {
-    __WASI_EINVAL
+    let linux_clock_id = match clock_id {
+        __WASI_CLOCK_MONOTONIC => CLOCK_MONOTONIC,
+        __WASI_CLOCK_PROCESS_CPUTIME_ID => CLOCK_PROCESS_CPUTIME_ID,
+        __WASI_CLOCK_REALTIME => CLOCK_REALTIME,
+        __WASI_CLOCK_THREAD_CPUTIME_ID => CLOCK_THREAD_CPUTIME_ID,
+        _ => return __WASI_EINVAL,
+    };
+
+    let output = unsafe {
+        let mut timespec_out: timespec = mem::uninitialized();
+        clock_getres(linux_clock_id, &mut timespec_out);
+    };
+
+    resolution.set(timespec_out.tv_nsec as __wasi_timestamp_t);
+
+    // TODO: map output of clock_getres to __wasi_errno_t
+    __WASI_ESUCCESS
 }
 
 pub fn platform_clock_time_get(
-    ctx: &mut Ctx,
     clock_id: __wasi_clockid_t,
     precision: __wasi_timestamp_t,
-    time: WasmPtr<__wasi_timestamp_t>,
+    time: &Cell<__wasi_timestamp_t>,
 ) -> __wasi_errno_t {
-    unimplemented!()
+    let linux_clock_id = match clock_id {
+        __WASI_CLOCK_MONOTONIC => CLOCK_MONOTONIC,
+        __WASI_CLOCK_PROCESS_CPUTIME_ID => CLOCK_PROCESS_CPUTIME_ID,
+        __WASI_CLOCK_REALTIME => CLOCK_REALTIME,
+        __WASI_CLOCK_THREAD_CPUTIME_ID => CLOCK_THREAD_CPUTIME_ID,
+        _ => return __WASI_EINVAL,
+    };
+
+    let output = unsafe {
+        let mut timespec_out: timespec = mem::uninitialized();
+        clock_gettime(linux_clock_id, precision, &mut timespec_out);
+    };
+
+    resolution.set(timespec_out.tv_nsec as __wasi_timestamp_t);
+
+    // TODO: map output of clock_gettime to __wasi_errno_t
+    __WASI_ESUCCESS
 }
diff --git a/lib/wasi/src/syscalls/unix/macos.rs b/lib/wasi/src/syscalls/unix/macos.rs
index 78ee51c9a..6273695d3 100644
--- a/lib/wasi/src/syscalls/unix/macos.rs
+++ b/lib/wasi/src/syscalls/unix/macos.rs
@@ -1,20 +1,17 @@
 use crate::syscalls::types::*;
-use crate::ptr::{Array, WasmPtr},
-use wasmer_runtime_core::{memory::Memory, vm::Ctx};
+use std::cell::Cell;
 
 pub fn platform_clock_res_get(
-    ctx: &mut Ctx,
     clock_id: __wasi_clockid_t,
-    resolution: WasmPtr<__wasi_timestamp_t>,
+    resolution: &Cell<__wasi_timestamp_t>,
 ) -> __wasi_errno_t {
     __WASI_EINVAL
 }
 
 pub fn platform_clock_time_get(
-    ctx: &mut Ctx,
     clock_id: __wasi_clockid_t,
     precision: __wasi_timestamp_t,
-    time: WasmPtr<__wasi_timestamp_t>,
+    time: &Cell<__wasi_timestamp_t>,
 ) -> __wasi_errno_t {
     unimplemented!()
 }
diff --git a/lib/wasi/src/syscalls/windows.rs b/lib/wasi/src/syscalls/windows.rs
index 78ee51c9a..6273695d3 100644
--- a/lib/wasi/src/syscalls/windows.rs
+++ b/lib/wasi/src/syscalls/windows.rs
@@ -1,20 +1,17 @@
 use crate::syscalls::types::*;
-use crate::ptr::{Array, WasmPtr},
-use wasmer_runtime_core::{memory::Memory, vm::Ctx};
+use std::cell::Cell;
 
 pub fn platform_clock_res_get(
-    ctx: &mut Ctx,
     clock_id: __wasi_clockid_t,
-    resolution: WasmPtr<__wasi_timestamp_t>,
+    resolution: &Cell<__wasi_timestamp_t>,
 ) -> __wasi_errno_t {
     __WASI_EINVAL
 }
 
 pub fn platform_clock_time_get(
-    ctx: &mut Ctx,
     clock_id: __wasi_clockid_t,
     precision: __wasi_timestamp_t,
-    time: WasmPtr<__wasi_timestamp_t>,
+    time: &Cell<__wasi_timestamp_t>,
 ) -> __wasi_errno_t {
     unimplemented!()
 }