diff --git a/Cargo.toml b/Cargo.toml
index 339944ce..769e4217 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,7 +11,7 @@ repository = "https://github.com/pyo3/pyo3"
 #documentation = "https://docs.rs/crate/pyo3/"
 categories = ["api-bindings", "development-tools::ffi"]
 license = "Apache-2.0"
-exclude = [".gitignore", ".travis.yml", ".cargo/config", "appveyor.yml"]
+exclude = ["/.gitignore", ".travis.yml", ".cargo/config", "appveyor.yml"]
 build = "build.rs"
 
 [badges]
diff --git a/build.rs b/build.rs
index 4e4cb45b..9ffb7642 100644
--- a/build.rs
+++ b/build.rs
@@ -175,7 +175,12 @@ fn run_python_script(interpreter: &str, script: &str) -> Result<String, String>
         .args(&["-c", script])
         .stderr(Stdio::inherit())
         .output()
-        .map_err(|e| format!("Failed to run the python interpreter at {}: {}", interpreter, e))?;
+        .map_err(|e| {
+            format!(
+                "Failed to run the python interpreter at {}: {}",
+                interpreter, e
+            )
+        })?;
 
     if !out.status.success() {
         return Err(format!("python script failed"));
diff --git a/examples/rustapi_module/src/lib.rs b/examples/rustapi_module/src/lib.rs
index 6c2ef34c..aadbb323 100644
--- a/examples/rustapi_module/src/lib.rs
+++ b/examples/rustapi_module/src/lib.rs
@@ -192,6 +192,13 @@ fn datetime_from_timestamp(py: Python, ts: f64, tz: Option<&PyTzInfo>) -> PyResu
     PyDateTime::from_timestamp(py, &args.to_object(py), &kwargs.to_object(py))
 }
 
+#[pyfunction]
+fn issue_219() -> PyResult<()> {
+    let gil = Python::acquire_gil();
+    let py = gil.python();
+    Ok(())
+}
+
 #[pymodinit]
 fn datetime(_py: Python, m: &PyModule) -> PyResult<()> {
     m.add_function(wrap_function!(make_date))?;
@@ -213,5 +220,7 @@ fn datetime(_py: Python, m: &PyModule) -> PyResult<()> {
         m.add_function(wrap_function!(get_datetime_tuple_fold));
     }
 
+    m.add_function(wrap_function!(issue_219))?;
+
     Ok(())
 }
diff --git a/examples/rustapi_module/tests/test_datetime.py b/examples/rustapi_module/tests/test_datetime.py
index ccfa6ae2..f41d5213 100644
--- a/examples/rustapi_module/tests/test_datetime.py
+++ b/examples/rustapi_module/tests/test_datetime.py
@@ -261,3 +261,5 @@ def test_delta_err(args, err_type):
     with pytest.raises(err_type):
         rdt.make_delta(*args)
 
+def test_issue_219():
+    rdt.issue_219()
diff --git a/pyo3-derive-backend/Cargo.toml b/pyo3-derive-backend/Cargo.toml
index 149edd7c..54eb52fb 100644
--- a/pyo3-derive-backend/Cargo.toml
+++ b/pyo3-derive-backend/Cargo.toml
@@ -12,4 +12,4 @@ license = "Apache-2.0"
 [dependencies]
 quote = "0.6.8"
 proc-macro2 = "0.4.19"
-syn = { version = "0.15.3", features = ["full", "extra-traits"] }
+syn = { version = "0.15.4", features = ["full", "extra-traits"] }
diff --git a/pyo3cls/Cargo.toml b/pyo3cls/Cargo.toml
index 293d5a29..5376d16a 100644
--- a/pyo3cls/Cargo.toml
+++ b/pyo3cls/Cargo.toml
@@ -15,5 +15,5 @@ proc-macro = true
 [dependencies]
 quote= "0.6.8"
 proc-macro2 = "0.4.19"
-syn = { version = "0.15.3", features = ["full", "extra-traits"] }
+syn = { version = "0.15.4", features = ["full", "extra-traits"] }
 pyo3-derive-backend = { path = "../pyo3-derive-backend", version = "=0.5.0" }