diff --git a/CHANGELOG.md b/CHANGELOG.md
index afe906514e8..144292117fa 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 ## **[Unreleased]**
 
+- [#940](https://github.com/wasmerio/wasmer/pull/940) Update supported Rust version to 1.38+
 - [#921](https://github.com/wasmerio/wasmer/pull/921) In LLVM backend, annotate all memory accesses with TBAA metadata.
 - [#883](https://github.com/wasmerio/wasmer/pull/883) Allow floating point operations to have arbitrary inputs, even including SNaNs.
 - [#856](https://github.com/wasmerio/wasmer/pull/856) Expose methods in the runtime C API to get a WASI import object
diff --git a/Cargo.toml b/Cargo.toml
index 2a47f943de4..0fe11919fb9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -7,6 +7,7 @@ repository = "https://github.com/wasmerio/wasmer"
 publish = true
 description = "High-Performance WebAssembly JIT interpreter"
 license = "MIT"
+default-run = "wasmer"
 include = [
     "examples/**/*",
     "src/**/*",
diff --git a/README.md b/README.md
index 7e7f39cb154..98533edf91b 100644
--- a/README.md
+++ b/README.md
@@ -181,7 +181,7 @@ nginx and Lua do not work on Windows - you can track the progress on [this issue
 
 ## Building
 
-[![Rustc Version 1.37+](https://img.shields.io/badge/rustc-1.37+-red.svg?style=flat-square)](https://blog.rust-lang.org/2019/08/15/Rust-1.37.0.html)
+[![Rustc Version 1.38+](https://img.shields.io/badge/rustc-1.37+-red.svg?style=flat-square)](https://blog.rust-lang.org/2019/09/26/Rust-1.38.0.html)
 
 Wasmer is built with [Cargo](https://crates.io/), the Rust package manager.
 
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index db05b2d340d..f86ead33af9 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -22,7 +22,7 @@ jobs:
       - script: cargo fmt --all -- --check
         displayName: Lint
     variables:
-      rust_toolchain: '1.37.0'
+      rust_toolchain: '1.38.0'
 
   - job: Test
     strategy:
@@ -39,7 +39,7 @@ jobs:
           CARGO_HTTP_CHECK_REVOKE: false
         windows:
           imageName: "vs2017-win2016"
-          rust_toolchain: '1.37.0'
+          rust_toolchain: '1.38.0'
     pool:
       vmImage: $(imageName)
     condition: in(variables['Build.SourceBranch'], 'refs/heads/master', 'refs/heads/staging', 'refs/heads/trying')
@@ -100,7 +100,7 @@ jobs:
           MACOSX_DEPLOYMENT_TARGET: 10.10
         windows:
           imageName: "vs2017-win2016"
-          rust_toolchain: '1.37.0'
+          rust_toolchain: '1.38.0'
           # RUSTFLAGS: -Ctarget-feature=+crt-static
     pool:
       vmImage: $(imageName)
@@ -163,7 +163,7 @@ jobs:
           MACOSX_DEPLOYMENT_TARGET: 10.10
         windows:
           imageName: "vs2017-win2016"
-          rust_toolchain: '1.37.0'
+          rust_toolchain: '1.38.0'
           # RUSTFLAGS: -Ctarget-feature=+crt-static
     pool:
       vmImage: $(imageName)
diff --git a/lib/singlepass-backend/src/emitter_x64.rs b/lib/singlepass-backend/src/emitter_x64.rs
index 251868231f1..a40d5b5e5f0 100644
--- a/lib/singlepass-backend/src/emitter_x64.rs
+++ b/lib/singlepass-backend/src/emitter_x64.rs
@@ -709,18 +709,14 @@ impl Emitter for Assembler {
         match (sz, src) {
             (Size::S64, Location::Imm32(src)) => dynasm!(self ; push src as i32),
             (Size::S64, Location::GPR(src)) => dynasm!(self ; push Rq(src as u8)),
-            (Size::S64, Location::Memory(src, disp)) => {
-                dynasm!(self ; push QWORD [Rq(src as u8) + disp])
-            }
+            (Size::S64, Location::Memory(src, disp)) => dynasm!(self ; push QWORD [Rq(src as u8) + disp]),
             _ => panic!("singlepass can't emit PUSH {:?} {:?}", sz, src),
         }
     }
     fn emit_pop(&mut self, sz: Size, dst: Location) {
         match (sz, dst) {
             (Size::S64, Location::GPR(dst)) => dynasm!(self ; pop Rq(dst as u8)),
-            (Size::S64, Location::Memory(dst, disp)) => {
-                dynasm!(self ; pop QWORD [Rq(dst as u8) + disp])
-            }
+            (Size::S64, Location::Memory(dst, disp)) => dynasm!(self ; pop QWORD [Rq(dst as u8) + disp]),
             _ => panic!("singlepass can't emit POP {:?} {:?}", sz, dst),
         }
     }
@@ -742,21 +738,13 @@ impl Emitter for Assembler {
     fn emit_neg(&mut self, sz: Size, value: Location) {
         match (sz, value) {
             (Size::S8, Location::GPR(value)) => dynasm!(self ; neg Rb(value as u8)),
-            (Size::S8, Location::Memory(value, disp)) => {
-                dynasm!(self ; neg [Rq(value as u8) + disp])
-            }
+            (Size::S8, Location::Memory(value, disp)) => dynasm!(self ; neg [Rq(value as u8) + disp]),
             (Size::S16, Location::GPR(value)) => dynasm!(self ; neg Rw(value as u8)),
-            (Size::S16, Location::Memory(value, disp)) => {
-                dynasm!(self ; neg [Rq(value as u8) + disp])
-            }
+            (Size::S16, Location::Memory(value, disp)) => dynasm!(self ; neg [Rq(value as u8) + disp]),
             (Size::S32, Location::GPR(value)) => dynasm!(self ; neg Rd(value as u8)),
-            (Size::S32, Location::Memory(value, disp)) => {
-                dynasm!(self ; neg [Rq(value as u8) + disp])
-            }
+            (Size::S32, Location::Memory(value, disp)) => dynasm!(self ; neg [Rq(value as u8) + disp]),
             (Size::S64, Location::GPR(value)) => dynasm!(self ; neg Rq(value as u8)),
-            (Size::S64, Location::Memory(value, disp)) => {
-                dynasm!(self ; neg [Rq(value as u8) + disp])
-            }
+            (Size::S64, Location::Memory(value, disp)) => dynasm!(self ; neg [Rq(value as u8) + disp]),
             _ => panic!("singlepass can't emit NEG {:?} {:?}", sz, value),
         }
     }
@@ -1009,30 +997,18 @@ impl Emitter for Assembler {
 
     fn emit_vmovaps(&mut self, src: XMMOrMemory, dst: XMMOrMemory) {
         match (src, dst) {
-            (XMMOrMemory::XMM(src), XMMOrMemory::XMM(dst)) => {
-                dynasm!(self ; movaps Rx(dst as u8), Rx(src as u8))
-            }
-            (XMMOrMemory::Memory(base, disp), XMMOrMemory::XMM(dst)) => {
-                dynasm!(self ; movaps Rx(dst as u8), [Rq(base as u8) + disp])
-            }
-            (XMMOrMemory::XMM(src), XMMOrMemory::Memory(base, disp)) => {
-                dynasm!(self ; movaps [Rq(base as u8) + disp], Rx(src as u8))
-            }
+            (XMMOrMemory::XMM(src), XMMOrMemory::XMM(dst)) => dynasm!(self ; movaps Rx(dst as u8), Rx(src as u8)),
+            (XMMOrMemory::Memory(base, disp), XMMOrMemory::XMM(dst)) => dynasm!(self ; movaps Rx(dst as u8), [Rq(base as u8) + disp]),
+            (XMMOrMemory::XMM(src), XMMOrMemory::Memory(base, disp)) => dynasm!(self ; movaps [Rq(base as u8) + disp], Rx(src as u8)),
             _ => panic!("singlepass can't emit VMOVAPS {:?} {:?}", src, dst),
         };
     }
 
     fn emit_vmovapd(&mut self, src: XMMOrMemory, dst: XMMOrMemory) {
         match (src, dst) {
-            (XMMOrMemory::XMM(src), XMMOrMemory::XMM(dst)) => {
-                dynasm!(self ; movapd Rx(dst as u8), Rx(src as u8))
-            }
-            (XMMOrMemory::Memory(base, disp), XMMOrMemory::XMM(dst)) => {
-                dynasm!(self ; movapd Rx(dst as u8), [Rq(base as u8) + disp])
-            }
-            (XMMOrMemory::XMM(src), XMMOrMemory::Memory(base, disp)) => {
-                dynasm!(self ; movapd [Rq(base as u8) + disp], Rx(src as u8))
-            }
+            (XMMOrMemory::XMM(src), XMMOrMemory::XMM(dst)) => dynasm!(self ; movapd Rx(dst as u8), Rx(src as u8)),
+            (XMMOrMemory::Memory(base, disp), XMMOrMemory::XMM(dst)) => dynasm!(self ; movapd Rx(dst as u8), [Rq(base as u8) + disp]),
+            (XMMOrMemory::XMM(src), XMMOrMemory::Memory(base, disp)) => dynasm!(self ; movapd [Rq(base as u8) + disp], Rx(src as u8)),
             _ => panic!("singlepass can't emit VMOVAPD {:?} {:?}", src, dst),
         };
     }
@@ -1104,77 +1080,57 @@ impl Emitter for Assembler {
 
     fn emit_vblendvps(&mut self, src1: XMM, src2: XMMOrMemory, mask: XMM, dst: XMM) {
         match src2 {
-            XMMOrMemory::XMM(src2) => {
-                dynasm!(self ; vblendvps Rx(dst as u8), Rx(mask as u8), Rx(src2 as u8), Rx(src1 as u8))
-            }
-            XMMOrMemory::Memory(base, disp) => {
-                dynasm!(self ; vblendvps Rx(dst as u8), Rx(mask as u8), [Rq(base as u8) + disp], Rx(src1 as u8))
-            }
+            XMMOrMemory::XMM(src2) => dynasm!(self ; vblendvps Rx(dst as u8), Rx(mask as u8), Rx(src2 as u8), Rx(src1 as u8)),
+            XMMOrMemory::Memory(base, disp) => dynasm!(self ; vblendvps Rx(dst as u8), Rx(mask as u8), [Rq(base as u8) + disp], Rx(src1 as u8)),
         }
     }
 
     fn emit_vblendvpd(&mut self, src1: XMM, src2: XMMOrMemory, mask: XMM, dst: XMM) {
         match src2 {
-            XMMOrMemory::XMM(src2) => {
-                dynasm!(self ; vblendvpd Rx(dst as u8), Rx(mask as u8), Rx(src2 as u8), Rx(src1 as u8))
-            }
-            XMMOrMemory::Memory(base, disp) => {
-                dynasm!(self ; vblendvpd Rx(dst as u8), Rx(mask as u8), [Rq(base as u8) + disp], Rx(src1 as u8))
-            }
+            XMMOrMemory::XMM(src2) => dynasm!(self ; vblendvpd Rx(dst as u8), Rx(mask as u8), Rx(src2 as u8), Rx(src1 as u8)),
+            XMMOrMemory::Memory(base, disp) => dynasm!(self ; vblendvpd Rx(dst as u8), Rx(mask as u8), [Rq(base as u8) + disp], Rx(src1 as u8)),
         }
     }
 
     fn emit_ucomiss(&mut self, src: XMMOrMemory, dst: XMM) {
         match src {
             XMMOrMemory::XMM(x) => dynasm!(self ; ucomiss Rx(dst as u8), Rx(x as u8)),
-            XMMOrMemory::Memory(base, disp) => {
-                dynasm!(self ; ucomiss Rx(dst as u8), [Rq(base as u8) + disp])
-            }
+            XMMOrMemory::Memory(base, disp) => dynasm!(self ; ucomiss Rx(dst as u8), [Rq(base as u8) + disp]),
         }
     }
 
     fn emit_ucomisd(&mut self, src: XMMOrMemory, dst: XMM) {
         match src {
             XMMOrMemory::XMM(x) => dynasm!(self ; ucomisd Rx(dst as u8), Rx(x as u8)),
-            XMMOrMemory::Memory(base, disp) => {
-                dynasm!(self ; ucomisd Rx(dst as u8), [Rq(base as u8) + disp])
-            }
+            XMMOrMemory::Memory(base, disp) => dynasm!(self ; ucomisd Rx(dst as u8), [Rq(base as u8) + disp]),
         }
     }
 
     fn emit_cvttss2si_32(&mut self, src: XMMOrMemory, dst: GPR) {
         match src {
             XMMOrMemory::XMM(x) => dynasm!(self ; cvttss2si Rd(dst as u8), Rx(x as u8)),
-            XMMOrMemory::Memory(base, disp) => {
-                dynasm!(self ; cvttss2si Rd(dst as u8), [Rq(base as u8) + disp])
-            }
+            XMMOrMemory::Memory(base, disp) => dynasm!(self ; cvttss2si Rd(dst as u8), [Rq(base as u8) + disp]),
         }
     }
 
     fn emit_cvttss2si_64(&mut self, src: XMMOrMemory, dst: GPR) {
         match src {
             XMMOrMemory::XMM(x) => dynasm!(self ; cvttss2si Rq(dst as u8), Rx(x as u8)),
-            XMMOrMemory::Memory(base, disp) => {
-                dynasm!(self ; cvttss2si Rq(dst as u8), [Rq(base as u8) + disp])
-            }
+            XMMOrMemory::Memory(base, disp) => dynasm!(self ; cvttss2si Rq(dst as u8), [Rq(base as u8) + disp]),
         }
     }
 
     fn emit_cvttsd2si_32(&mut self, src: XMMOrMemory, dst: GPR) {
         match src {
             XMMOrMemory::XMM(x) => dynasm!(self ; cvttsd2si Rd(dst as u8), Rx(x as u8)),
-            XMMOrMemory::Memory(base, disp) => {
-                dynasm!(self ; cvttsd2si Rd(dst as u8), [Rq(base as u8) + disp])
-            }
+            XMMOrMemory::Memory(base, disp) => dynasm!(self ; cvttsd2si Rd(dst as u8), [Rq(base as u8) + disp]),
         }
     }
 
     fn emit_cvttsd2si_64(&mut self, src: XMMOrMemory, dst: GPR) {
         match src {
             XMMOrMemory::XMM(x) => dynasm!(self ; cvttsd2si Rq(dst as u8), Rx(x as u8)),
-            XMMOrMemory::Memory(base, disp) => {
-                dynasm!(self ; cvttsd2si Rq(dst as u8), [Rq(base as u8) + disp])
-            }
+            XMMOrMemory::Memory(base, disp) => dynasm!(self ; cvttsd2si Rq(dst as u8), [Rq(base as u8) + disp]),
         }
     }