diff --git a/.travis.yml b/.travis.yml
index 31d10e84ee..ac5a7b8ab7 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,20 +5,26 @@ matrix:
     # NOTE used to build docs on successful merges to master
     - env: TARGET=x86_64-unknown-linux-gnu
 
+      # MSRV
+    - env: TARGET=thumbv7m-none-eabi
+      rust: 1.36.0
+      if: (branch = staging OR branch = trying) OR (type = pull_request AND branch = master)
+
     - env: TARGET=thumbv6m-none-eabi
       if: (branch = staging OR branch = trying) OR (type = pull_request AND branch = master)
 
     - env: TARGET=thumbv7m-none-eabi
       if: (branch = staging OR branch = trying) OR (type = pull_request AND branch = master)
 
+      # compile-fail tests
     - env: TARGET=x86_64-unknown-linux-gnu
       rust: nightly
       if: (branch = staging OR branch = trying) OR (type = pull_request AND branch = master)
 
+      # heterogeneous multi-core support
     - env: TARGET=thumbv6m-none-eabi
       rust: nightly
       if: (branch = staging OR branch = trying) OR (type = pull_request AND branch = master)
-
     - env: TARGET=thumbv7m-none-eabi
       rust: nightly
       if: (branch = staging OR branch = trying) OR (type = pull_request AND branch = master)
diff --git a/macros/Cargo.toml b/macros/Cargo.toml
index c4e897fa6e..ed7626f84e 100644
--- a/macros/Cargo.toml
+++ b/macros/Cargo.toml
@@ -15,9 +15,9 @@ version = "0.5.0-alpha.1"
 proc-macro = true
 
 [dependencies]
-proc-macro2 = "0.4.30"
-quote = "0.6.12"
-syn = "0.15.34"
+proc-macro2 = "1"
+quote = "1"
+syn = "1"
 
 [dependencies.rtfm-syntax]
 git = "https://github.com/japaric/rtfm-syntax"
diff --git a/macros/src/check.rs b/macros/src/check.rs
index 85fda75b30..0136370ce1 100644
--- a/macros/src/check.rs
+++ b/macros/src/check.rs
@@ -169,9 +169,10 @@ pub fn app<'a>(app: &'a App, analysis: &Analysis) -> parse::Result<Extra<'a>> {
                     peripherals = if *x { Some(0) } else { None }
                 }
 
-                CustomArg::UInt(x) if app.args.cores != 1 => {
-                    peripherals = if *x < u64::from(app.args.cores) {
-                        Some(*x as u8)
+                CustomArg::UInt(s) if app.args.cores != 1 => {
+                    let x = s.parse::<u8>().ok();
+                    peripherals = if x.is_some() && x.unwrap() < app.args.cores {
+                        Some(x.unwrap())
                     } else {
                         return Err(parse::Error::new(
                             k.span(),
diff --git a/macros/src/codegen.rs b/macros/src/codegen.rs
index 8ac06d5343..0213848157 100644
--- a/macros/src/codegen.rs
+++ b/macros/src/codegen.rs
@@ -126,7 +126,7 @@ pub fn app(app: &App, analysis: &Analysis, extra: &Extra) -> TokenStream2 {
 
         #(#root)*
 
-        #(#mod_resources)*
+        #mod_resources
 
         #(#root_hardware_tasks)*
 
diff --git a/macros/src/codegen/hardware_tasks.rs b/macros/src/codegen/hardware_tasks.rs
index cf92e07867..a9c2a2bdc7 100644
--- a/macros/src/codegen/hardware_tasks.rs
+++ b/macros/src/codegen/hardware_tasks.rs
@@ -115,6 +115,7 @@ pub fn codegen(
         let stmts = &task.stmts;
         let section = util::link_section("text", core);
         // XXX shouldn't this have a cfg_core?
+        let locals_pat = locals_pat.iter();
         user_tasks.push(quote!(
             #(#attrs)*
             #[allow(non_snake_case)]
diff --git a/macros/src/codegen/idle.rs b/macros/src/codegen/idle.rs
index d6560761c0..35a7252307 100644
--- a/macros/src/codegen/idle.rs
+++ b/macros/src/codegen/idle.rs
@@ -58,6 +58,7 @@ pub fn codegen(
         let context = &idle.context;
         let stmts = &idle.stmts;
         let section = util::link_section("text", core);
+        let locals_pat = locals_pat.iter();
         let user_idle = Some(quote!(
             #(#attrs)*
             #[allow(non_snake_case)]
@@ -70,6 +71,7 @@ pub fn codegen(
             }
         ));
 
+        let locals_new = locals_new.iter();
         let call_idle = quote!(#name(
             #(#locals_new,)*
             #name::Context::new(&rtfm::export::Priority::new(0))
diff --git a/macros/src/codegen/init.rs b/macros/src/codegen/init.rs
index 878c633eaf..9c8ce31c7c 100644
--- a/macros/src/codegen/init.rs
+++ b/macros/src/codegen/init.rs
@@ -83,6 +83,7 @@ pub fn codegen(
         let attrs = &init.attrs;
         let stmts = &init.stmts;
         let section = util::link_section("text", core);
+        let locals_pat = locals_pat.iter();
         let user_init = Some(quote!(
             #(#attrs)*
             #cfg_core
@@ -102,6 +103,7 @@ pub fn codegen(
             const_app = Some(constructor);
         }
 
+        let locals_new = locals_new.iter();
         let call_init =
             Some(quote!(let late = #name(#(#locals_new,)* #name::Context::new(core.into()));));
 
diff --git a/macros/src/codegen/software_tasks.rs b/macros/src/codegen/software_tasks.rs
index 2960faf965..be1eb05cb5 100644
--- a/macros/src/codegen/software_tasks.rs
+++ b/macros/src/codegen/software_tasks.rs
@@ -168,6 +168,7 @@ pub fn codegen(
         let attrs = &task.attrs;
         let cfgs = &task.cfgs;
         let stmts = &task.stmts;
+        let locals_pat = locals_pat.iter();
         user_tasks.push(quote!(
             #(#attrs)*
             #(#cfgs)*
diff --git a/macros/src/codegen/util.rs b/macros/src/codegen/util.rs
index f5f96deaa4..207272dc90 100644
--- a/macros/src/codegen/util.rs
+++ b/macros/src/codegen/util.rs
@@ -3,13 +3,13 @@ use core::sync::atomic::{AtomicUsize, Ordering};
 use proc_macro2::{Span, TokenStream as TokenStream2};
 use quote::quote;
 use rtfm_syntax::{ast::App, Context, Core};
-use syn::{ArgCaptured, Attribute, Ident, IntSuffix, LitInt};
+use syn::{Attribute, Ident, LitInt, PatType};
 
 use crate::check::Extra;
 
 /// Turns `capacity` into an unsuffixed integer literal
 pub fn capacity_literal(capacity: u8) -> LitInt {
-    LitInt::new(u64::from(capacity), IntSuffix::None, Span::call_site())
+    LitInt::new(&capacity.to_string(), Span::call_site())
 }
 
 /// Turns `capacity` into a type-level (`typenum`) integer
@@ -194,7 +194,7 @@ pub fn rendezvous_ident(core: Core) -> Ident {
 //
 // `inputs` could be &[`input: Foo`] OR &[`mut x: i32`, `ref y: i64`]
 pub fn regroup_inputs(
-    inputs: &[ArgCaptured],
+    inputs: &[PatType],
 ) -> (
     // args e.g. &[`_0`],  &[`_0: i32`, `_1: i64`]
     Vec<TokenStream2>,
diff --git a/macros/src/lib.rs b/macros/src/lib.rs
index ed55095dc2..7a436e7b85 100644
--- a/macros/src/lib.rs
+++ b/macros/src/lib.rs
@@ -1,5 +1,4 @@
 #![deny(warnings)]
-#![recursion_limit = "128"]
 
 extern crate proc_macro;
 
diff --git a/tests/single.rs b/tests/single.rs
index 93addf6e02..01b80312cb 100644
--- a/tests/single.rs
+++ b/tests/single.rs
@@ -8,8 +8,10 @@ fn ui() {
 
     config.mode = Mode::Ui;
     config.src_base = PathBuf::from("ui/single");
-    config.target_rustcflags =
-        Some("--edition=2018 -L target/debug/deps -Z unstable-options --extern rtfm --extern lm3s6965".to_owned());
+    config.target_rustcflags = Some(
+        "--edition=2018 -L target/debug/deps -Z unstable-options --extern rtfm --extern lm3s6965"
+            .to_owned(),
+    );
     config.link_deps();
     config.clean_rmeta();