diff --git a/.github/workflows/cross_platform.yml b/.github/workflows/cross_platform.yml
new file mode 100644
index 00000000..3125393d
--- /dev/null
+++ b/.github/workflows/cross_platform.yml
@@ -0,0 +1,79 @@
+{
+  "name": "Cross platform tests",
+  "on": {
+    "push": {
+      "branches": [
+        "trunk",
+        "v*.x",
+        "ci/*"
+      ]
+    },
+    "pull_request": {
+      "branches": [
+        "trunk",
+        "v*.x"
+      ]
+    }
+  },
+  "jobs": {
+    "check": {
+      "name": "Test",
+      "runs-on": "ubuntu-latest",
+      "strategy": {
+        "fail-fast": false,
+        "matrix": {
+          "platform": [
+            "aarch64-unknown-linux-gnu",
+            "arm-unknown-linux-gnueabi",
+            "arm-unknown-linux-gnueabihf",
+            # "armv5te-unknown-linux-gnueabi",
+            "armv7-unknown-linux-gnueabihf",
+            "i586-unknown-linux-gnu",
+            # "i686-pc-windows-gnu",
+            "i686-unknown-linux-gnu",
+            # "mips-unknown-linux-gnu",
+            "mips64-unknown-linux-gnuabi64",
+            "mips64el-unknown-linux-gnuabi64",
+            # "mipsel-unknown-linux-gnu",
+            # "powerpc-unknown-linux-gnu",
+            # "powerpc64-unknown-linux-gnu",
+            # "powerpc64le-unknown-linux-gnu",
+            "riscv64gc-unknown-linux-gnu",
+            # "sparc64-unknown-linux-gnu",
+            "x86_64-pc-windows-gnu",
+            "x86_64-unknown-linux-gnu"
+          ]
+        }
+      },
+      "steps": [
+        {
+          "uses": "actions/checkout@v2",
+          "name": "Checkout"
+        },
+        {
+          "uses": "actions-rs/toolchain@v1",
+          "with": {
+            "profile": "minimal",
+            "toolchain": "stable",
+            "override": true
+          },
+          "name": "Install Rust stable"
+        },
+        {
+          "uses": "actions-rs/install@v0.1",
+          "with": {
+            "crate": "cross"
+          },
+          "name": "Install cargo cross"
+        },
+        {
+          "run": "cross test --target ${{ matrix.platform }}",
+          "name": "Run tests",
+          "env": {
+            "RUSTFLAGS": "-D warnings"
+          }
+        }
+      ]
+    }
+  }
+}
diff --git a/src/enc/impls.rs b/src/enc/impls.rs
index 0269a1b6..0f061acd 100644
--- a/src/enc/impls.rs
+++ b/src/enc/impls.rs
@@ -134,8 +134,8 @@ impl Encode for usize {
                 crate::varint::varint_encode_usize(encoder.writer(), E::C::ENDIAN, *self)
             }
             IntEncoding::Fixed => match E::C::ENDIAN {
-                Endian::Big => encoder.writer().write(&self.to_be_bytes()),
-                Endian::Little => encoder.writer().write(&self.to_le_bytes()),
+                Endian::Big => encoder.writer().write(&(*self as u64).to_be_bytes()),
+                Endian::Little => encoder.writer().write(&(*self as u64).to_le_bytes()),
             },
         }
     }
@@ -246,8 +246,8 @@ impl Encode for isize {
                 crate::varint::varint_encode_isize(encoder.writer(), E::C::ENDIAN, *self)
             }
             IntEncoding::Fixed => match E::C::ENDIAN {
-                Endian::Big => encoder.writer().write(&self.to_be_bytes()),
-                Endian::Little => encoder.writer().write(&self.to_le_bytes()),
+                Endian::Big => encoder.writer().write(&(*self as i64).to_be_bytes()),
+                Endian::Little => encoder.writer().write(&(*self as i64).to_le_bytes()),
             },
         }
     }
diff --git a/tests/alloc.rs b/tests/alloc.rs
index 84bffe09..3173ed74 100644
--- a/tests/alloc.rs
+++ b/tests/alloc.rs
@@ -115,7 +115,13 @@ fn test_container_limits() {
             bincode::config::standard().with_limit::<DECODE_LIMIT>(),
         );
 
-        assert_eq!(result.unwrap_err(), DecodeError::LimitExceeded);
+        let name = core::any::type_name::<T>();
+        match result {
+            Ok(_) => panic!("Decoding {} should fail, it instead succeeded", name),
+            Err(DecodeError::OutsideUsizeRange(_)) if cfg!(target_pointer_width = "32") => {},
+            Err(DecodeError::LimitExceeded) => {},
+            Err(e) => panic!("Expected OutsideUsizeRange (on 32 bit platforms) or LimitExceeded whilst decoding {}, got {:?}", name, e),
+        }
     }
 
     for slice in test_cases {