diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
new file mode 100644
index 0000000000000000000000000000000000000000..ab7b403383dfccfd255f803981186e416f48e52f
--- /dev/null
+++ b/.github/workflows/windows.yml
@@ -0,0 +1,58 @@
+name: continuous-intergration/windows
+
+on:
+  pull_request:
+  push:
+    branches:
+      - master
+    tags:
+      - v*
+    paths-ignore:
+      - 'README.md'
+
+jobs:
+  check:
+    name: build-contract-template
+    strategy:
+      matrix:
+        platform:
+          - windows-latest
+        toolchain:
+          - nightly
+    runs-on: ${{ matrix.platform }}
+    env:
+      RUST_BACKTRACE: full
+    steps:
+
+      - uses: engineerd/configurator@v0.0.6
+        with:
+          name: "wasm-opt.exe"
+          url: "https://github.com/WebAssembly/binaryen/releases/download/version_101/binaryen-version_101-x86_64-windows.tar.gz"
+          pathInArchive: "binaryen-version_101/bin/wasm-opt.exe"
+
+      - name: Checkout sources & submodules
+        uses: actions/checkout@master
+        with:
+          fetch-depth: 1
+          submodules: recursive
+
+      - name: Install toolchain
+        id: toolchain
+        uses: actions-rs/toolchain@master
+        with:
+          profile: minimal
+          toolchain: ${{ matrix.toolchain }}
+          components: rust-src
+          override: true
+
+      - name:                      Rust Cache
+        uses:                      Swatinem/rust-cache@v1.2.0
+
+      - name: Build contract template on ${{ matrix.platform }}-${{ matrix.toolchain }}
+        run: |
+          wasm-opt --version
+          cargo -vV
+          cargo run -- contract --version
+          cargo run -- contract new foobar
+          echo "[workspace]" >> foobar/Cargo.toml
+          cargo run -- contract build --manifest-path=foobar/Cargo.toml
diff --git a/CHANGELOG.md b/CHANGELOG.md
index ca1ce2f450adc0354570cc7ebbd50dc2d5f622d3..1ab49a3af61f6a4930c168453734b59264f297bd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+- Fixed `ERROR: The workspace root package should be a workspace member` when building a contract
+  under Windows - [#261](https://github.com/paritytech/cargo-contract/pull/261)
+
 ### Removed
 - Remove support for `--binaryen-as-dependency` - [#251](https://github.com/paritytech/cargo-contract/pull/251)
 
diff --git a/Cargo.lock b/Cargo.lock
index 21204c1ef1f4088211d57509cc9ed1f05875fd89..2fcd996e676469da9d2c7e9dd96fa6758fe11bb2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -307,27 +307,6 @@ version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b41b7ea54a0c9d92199de89e20e58d49f02f8e699814ef3fdf266f6f748d15c7"
 
-[[package]]
-name = "binaryen"
-version = "0.12.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1a9b407f52d0b918c6ea41d7a328321496b315f61da99a309b375dfbbd04bc9a"
-dependencies = [
- "binaryen-sys",
-]
-
-[[package]]
-name = "binaryen-sys"
-version = "0.12.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "86e9636d01b92f2df45dce29c35a9e3724687c1055bb4472fb4b829cc4a5a561"
-dependencies = [
- "cc",
- "cmake",
- "heck",
- "regex",
-]
-
 [[package]]
 name = "bitflags"
 version = "1.2.1"
@@ -500,7 +479,6 @@ dependencies = [
  "anyhow",
  "assert_matches",
  "async-std",
- "binaryen",
  "blake2",
  "cargo_metadata",
  "colored",
diff --git a/Cargo.toml b/Cargo.toml
index ddcfbff60f9f1ac81668fb05401704614f1dc50f..da3e7c228fe360495fd1e1137a8bf1aa3fe75ac9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -40,7 +40,6 @@ serde = { version = "1.0.125", default-features = false, features = ["derive"] }
 serde_json = "1.0.64"
 tempfile = "3.2.0"
 url = { version = "2.2.1", features = ["serde"] }
-binaryen = { version = "0.12.0", optional = true }
 impl-serde = "0.3.1"
 regex = "1.4"
 
diff --git a/src/cmd/build.rs b/src/cmd/build.rs
index a0a19a76172331e10cfb89968ac0393111970f77..0e12b9546d1045d0b057b34832c9971d5d51e031 100644
--- a/src/cmd/build.rs
+++ b/src/cmd/build.rs
@@ -596,9 +596,10 @@ mod tests_ci_only {
         BuildArtifacts, ManifestPath, OptimizationPasses, UnstableFlags, UnstableOptions,
         Verbosity, VerbosityFlags,
     };
+    #[cfg(unix)]
+    use std::os::unix::fs::PermissionsExt;
     use std::{
         io::Write,
-        os::unix::fs::PermissionsExt,
         path::{Path, PathBuf},
     };
 
@@ -623,6 +624,9 @@ mod tests_ci_only {
     /// "wasm-opt version `version`".
     ///
     /// Returns the path to this file.
+    ///
+    /// Currently works only on `unix`.
+    #[cfg(unix)]
     fn mock_wasm_opt_version(tmp_dir: &Path, version: &str) -> PathBuf {
         let path = tmp_dir.join("wasm-opt-mocked");
         {
@@ -829,6 +833,7 @@ mod tests_ci_only {
         })
     }
 
+    #[cfg(unix)]
     #[test]
     fn incompatible_wasm_opt_version_must_be_detected_if_built_from_repo() {
         with_tmp_dir(|path| {
@@ -849,6 +854,7 @@ mod tests_ci_only {
         })
     }
 
+    #[cfg(unix)]
     #[test]
     fn compatible_wasm_opt_version_must_be_detected_if_built_from_repo() {
         with_tmp_dir(|path| {
@@ -865,6 +871,7 @@ mod tests_ci_only {
         })
     }
 
+    #[cfg(unix)]
     #[test]
     fn incompatible_wasm_opt_version_must_be_detected_if_installed_as_package() {
         with_tmp_dir(|path| {
@@ -885,6 +892,7 @@ mod tests_ci_only {
         })
     }
 
+    #[cfg(unix)]
     #[test]
     fn compatible_wasm_opt_version_must_be_detected_if_installed_as_package() {
         with_tmp_dir(|path| {
diff --git a/src/workspace/manifest.rs b/src/workspace/manifest.rs
index 5a439926bb65c43cf82319afdc7212b45c1fb685..fc2a52ed25a1e947dab0d68b451a46dae016c340 100644
--- a/src/workspace/manifest.rs
+++ b/src/workspace/manifest.rs
@@ -177,6 +177,7 @@ impl Manifest {
     }
 
     /// Set `optimization-passes` in `[package.metadata.contract]`
+    #[cfg(feature = "test-ci-only")]
     #[cfg(test)]
     pub fn set_profile_optimization_passes(
         &mut self,
@@ -205,6 +206,7 @@ impl Manifest {
     }
 
     /// Set the dependency version of `package` to `version`.
+    #[cfg(feature = "test-ci-only")]
     #[cfg(test)]
     pub fn set_dependency_version(
         &mut self,
diff --git a/src/workspace/mod.rs b/src/workspace/mod.rs
index 7f242d2a0f1c7e8435beb4100dc3196971cc2024..733e8700ffa5bfd9d6a839dcf6cf1061d0a11450 100644
--- a/src/workspace/mod.rs
+++ b/src/workspace/mod.rs
@@ -108,14 +108,24 @@ impl Workspace {
             .members
             .iter_mut()
             .find_map(|(_, (_, manifest))| {
-                if manifest.path().directory() == Some(package_path) {
+                // `package_path` is always absolute and canonicalized. Thus we need to
+                // canonicalize the manifest's directory path as well in order to compare
+                // both of them.
+                let manifest_path = manifest.path().directory()?;
+                let manifest_path = manifest_path
+                    .canonicalize()
+                    .unwrap_or_else(|_| panic!("Cannot canonicalize {}", manifest_path.display()));
+                if manifest_path == package_path {
                     Some(manifest)
                 } else {
                     None
                 }
             })
             .ok_or_else(|| {
-                anyhow::anyhow!("The workspace root package should be a workspace member")
+                anyhow::anyhow!(
+                    "Cannot find package with package path {} in workspace members",
+                    package_path.display(),
+                )
             })?;
         f(manifest)?;
         Ok(self)