diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index 1b874f728..0555b2880 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -94,6 +94,62 @@ jobs:
           command: check
           args: --no-default-features --features serde,rand --target thumbv7em-none-eabihf
 
+  check-web:
+    name: Type checking (web)
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        rust: [1.32.0, 1.36.0, stable] # 1.36 is when alloc was stabilized
+
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v2
+
+      - name: Install cargo-web
+        uses: actions-rs/install@v0.1
+        with:
+          crate: cargo-web
+          use-tool-cache: true
+
+      - name: Cache target
+        uses: actions/cache@v1
+        env:
+          cache-name: target
+        with:
+          path: ./target
+          key: ubuntu-latest-typecheck-target-${{ matrix.rust }}-web
+
+      - name: Install toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: ${{ matrix.rust }}
+          target: wasm32-unknown-unknown
+          override: true
+
+      # ensure `#![no_std]` support
+      - name: Run `cargo web check --no-default-features`
+        uses: actions-rs/cargo@v1
+        with:
+          command: web
+          args: check --no-default-features
+        if: matrix.rust != '1.32.0' # alloc is unstable in 1.32
+
+      # `#![no_std]` with serde, rand
+      - name: Run `cargo web check --no-default-features --features serde,rand`
+        uses: actions-rs/cargo@v1
+        with:
+          command: web
+          args: check --no-default-features --features serde,rand
+        if: matrix.rust != '1.32.0' # alloc is unstable in 1.32
+
+      # everything
+      - name: Run `cargo check --features serde,deprecated,panicking-api,rand`
+        uses: actions-rs/cargo@v1
+        with:
+          command: check
+          args: --features serde,deprecated,panicking-api,rand
+
   test:
     name: Test suite
     runs-on: ${{ matrix.os }}
@@ -191,7 +247,7 @@ jobs:
     name: Documentation
     runs-on: ubuntu-latest
     # ensure docs only get pushed if everything else is successful
-    needs: [check, test, fmt, clippy]
+    needs: [check, check-embedded, check-web, test, fmt, clippy]
 
     steps:
       - name: Checkout
diff --git a/src/utc_offset.rs b/src/utc_offset.rs
index 5ec07676a..e77755dc7 100644
--- a/src/utc_offset.rs
+++ b/src/utc_offset.rs
@@ -3,8 +3,6 @@ use crate::{
     internal_prelude::*,
 };
 use core::fmt::{self, Display};
-#[cfg(cargo_web)]
-use stdweb::js;
 
 /// An offset from UTC.
 ///
@@ -490,7 +488,7 @@ fn try_local_offset_at(datetime: OffsetDateTime) -> Option<UtcOffset> {
 
             diff_secs.try_into().ok().map(UtcOffset::seconds)
         } else if #[cfg(cargo_web)] {
-            use stdweb::unstable::TryInto;
+            use stdweb::js;
 
             let timestamp_utc = datetime.timestamp();
             let low_bits = (timestamp_utc & 0xFF_FF_FF_FF) as i32;
@@ -502,7 +500,7 @@ fn try_local_offset_at(datetime: OffsetDateTime) -> Option<UtcOffset> {
                         .getTimezoneOffset() * -60;
             };
 
-            timezone_offset.try_into().ok().map(UtcOffset::seconds)
+            stdweb::unstable::TryInto::try_into(timezone_offset).ok().map(UtcOffset::seconds)
         } else {
             None
         }