diff --git a/src/api/custom_syntax.rs b/src/api/custom_syntax.rs
index 91b89b2c..f0368b9a 100644
--- a/src/api/custom_syntax.rs
+++ b/src/api/custom_syntax.rs
@@ -402,7 +402,8 @@ impl Engine {
                     parse: Box::new(parse),
                     func: Box::new(func),
                     scope_may_be_changed,
-                },
+                }
+                .into(),
             );
         self
     }
diff --git a/src/api/events.rs b/src/api/events.rs
index 1b7d0749..7fd2dafd 100644
--- a/src/api/events.rs
+++ b/src/api/events.rs
@@ -363,7 +363,7 @@ impl Engine {
             + SendSync
             + 'static,
     ) -> &mut Self {
-        self.debugger_interface = Some(Box::new((Box::new(init), Box::new(callback))));
+        self.debugger_interface = Some((Box::new(init), Box::new(callback)));
         self
     }
 }
diff --git a/src/engine.rs b/src/engine.rs
index 255ab7eb..1e35d21f 100644
--- a/src/engine.rs
+++ b/src/engine.rs
@@ -115,7 +115,7 @@ pub struct Engine {
     /// Custom syntax.
     #[cfg(not(feature = "no_custom_syntax"))]
     pub(crate) custom_syntax: Option<
-        Box<std::collections::BTreeMap<Identifier, crate::api::custom_syntax::CustomSyntax>>,
+        Box<std::collections::BTreeMap<Identifier, Box<crate::api::custom_syntax::CustomSyntax>>>,
     >,
     /// Callback closure for filtering variable definition.
     pub(crate) def_var_filter: Option<Box<OnDefVarCallback>>,
@@ -147,12 +147,10 @@ pub struct Engine {
 
     /// Callback closure for debugging.
     #[cfg(feature = "debugging")]
-    pub(crate) debugger_interface: Option<
-        Box<(
-            Box<crate::eval::OnDebuggingInit>,
-            Box<crate::eval::OnDebuggerCallback>,
-        )>,
-    >,
+    pub(crate) debugger_interface: Option<(
+        Box<crate::eval::OnDebuggingInit>,
+        Box<crate::eval::OnDebuggerCallback>,
+    )>,
 }
 
 impl fmt::Debug for Engine {
diff --git a/src/eval/data_check.rs b/src/eval/data_check.rs
index e4e5dc68..f5016ea3 100644
--- a/src/eval/data_check.rs
+++ b/src/eval/data_check.rs
@@ -205,9 +205,13 @@ impl Engine {
         }
 
         // Report progress
-        self.progress
-            .as_ref()
-            .and_then(|p| p(global.num_operations))
-            .map_or(Ok(()), |token| Err(ERR::ErrorTerminated(token, pos).into()))
+        if let Some(ref progress) = self.progress {
+            match progress(global.num_operations) {
+                None => Ok(()),
+                Some(token) => Err(ERR::ErrorTerminated(token, pos).into()),
+            }
+        } else {
+            Ok(())
+        }
     }
 }
diff --git a/src/eval/debugger.rs b/src/eval/debugger.rs
index 0302bdc2..de0bdd64 100644
--- a/src/eval/debugger.rs
+++ b/src/eval/debugger.rs
@@ -510,7 +510,7 @@ impl Engine {
             let src = global.source_raw().cloned();
             let src = src.as_ref().map(|s| s.as_str());
             let context = EvalContext::new(self, global, caches, scope, this_ptr);
-            let (.., ref on_debugger) = **x;
+            let (.., ref on_debugger) = *x;
 
             let command = on_debugger(context, event, node, src, node.position());
 
diff --git a/src/func/call.rs b/src/func/call.rs
index a47c3495..f28d6f08 100644
--- a/src/func/call.rs
+++ b/src/func/call.rs
@@ -464,7 +464,7 @@ impl Engine {
                             let t = self.map_type_name(type_name::<ImmutableString>()).into();
                             ERR::ErrorMismatchOutputType(t, typ.into(), pos)
                         })?;
-                        ((print)(&text).into(), false)
+                        (print(&text).into(), false)
                     } else {
                         (Dynamic::UNIT, false)
                     }
@@ -475,7 +475,7 @@ impl Engine {
                             let t = self.map_type_name(type_name::<ImmutableString>()).into();
                             ERR::ErrorMismatchOutputType(t, typ.into(), pos)
                         })?;
-                        ((debug)(&text, global.source(), pos).into(), false)
+                        (debug(&text, global.source(), pos).into(), false)
                     } else {
                         (Dynamic::UNIT, false)
                     }
diff --git a/src/optimizer.rs b/src/optimizer.rs
index c2dcb0c1..021a62d0 100644
--- a/src/optimizer.rs
+++ b/src/optimizer.rs
@@ -1139,7 +1139,7 @@ fn optimize_expr(expr: &mut Expr, state: &mut OptimizerState, _chaining: bool) {
                         .and_then(|(f, ctx)| {
                             let context = ctx.then(|| (state.engine, x.name.as_str(), None, &state.global, *pos).into());
                             let (first, second) = arg_values.split_first_mut().unwrap();
-                            (f)(context, &mut [ first, &mut second[0] ]).ok()
+                            f(context, &mut [ first, &mut second[0] ]).ok()
                         }) {
                             state.set_dirty();
                             *expr = Expr::from_dynamic(result, *pos);
diff --git a/src/tests.rs b/src/tests.rs
index e6f07dd4..de018e67 100644
--- a/src/tests.rs
+++ b/src/tests.rs
@@ -13,6 +13,7 @@ fn check_struct_sizes() {
         feature = "only_i32",
         any(feature = "no_float", feature = "f32_float")
     ));
+    const WORD_SIZE: usize = size_of::<usize>();
 
     assert_eq!(size_of::<Dynamic>(), if PACKED { 8 } else { 16 });
     assert_eq!(size_of::<Option<Dynamic>>(), if PACKED { 8 } else { 16 });
@@ -20,10 +21,7 @@ fn check_struct_sizes() {
         size_of::<Position>(),
         if cfg!(feature = "no_position") { 0 } else { 4 }
     );
-    assert_eq!(
-        size_of::<tokenizer::Token>(),
-        if IS_32_BIT { 8 } else { 16 }
-    );
+    assert_eq!(size_of::<tokenizer::Token>(), 2 * WORD_SIZE);
     assert_eq!(size_of::<ast::Expr>(), if PACKED { 12 } else { 16 });
     assert_eq!(size_of::<Option<ast::Expr>>(), if PACKED { 12 } else { 16 });
     assert_eq!(size_of::<ast::Stmt>(), if IS_32_BIT { 12 } else { 16 });
@@ -34,40 +32,41 @@ fn check_struct_sizes() {
 
     #[cfg(feature = "internals")]
     {
-        assert_eq!(
-            size_of::<CallableFunction>(),
-            if IS_32_BIT { 12 } else { 24 }
-        );
-        assert_eq!(
-            size_of::<module::FuncInfo>(),
-            if IS_32_BIT { 16 } else { 32 }
-        );
+        assert_eq!(size_of::<CallableFunction>(), 3 * WORD_SIZE);
+        assert_eq!(size_of::<module::FuncInfo>(), 4 * WORD_SIZE);
     }
 
-    #[cfg(target_pointer_width = "64")]
-    {
-        assert_eq!(size_of::<Scope>(), 536);
-        assert_eq!(
-            size_of::<FnPtr>(),
-            if cfg!(feature = "no_function") {
-                72
-            } else {
-                80
-            }
-        );
-        assert_eq!(size_of::<LexError>(), 56);
-        assert_eq!(
-            size_of::<ParseError>(),
-            if cfg!(feature = "no_position") { 8 } else { 16 }
-        );
-        assert_eq!(size_of::<EvalAltResult>(), 64);
-        assert_eq!(
-            size_of::<NativeCallContext>(),
-            if cfg!(feature = "no_position") {
-                48
-            } else {
-                56
-            }
-        );
+    // The following only on 64-bit platforms
+
+    if !cfg!(target_pointer_width = "64") {
+        return;
     }
+
+    assert_eq!(size_of::<Scope>(), 536);
+    assert_eq!(
+        size_of::<FnPtr>(),
+        80 - if cfg!(feature = "no_function") {
+            WORD_SIZE
+        } else {
+            0
+        }
+    );
+    assert_eq!(size_of::<LexError>(), 56);
+    assert_eq!(
+        size_of::<ParseError>(),
+        16 - if cfg!(feature = "no_position") {
+            WORD_SIZE
+        } else {
+            0
+        }
+    );
+    assert_eq!(size_of::<EvalAltResult>(), 64);
+    assert_eq!(
+        size_of::<NativeCallContext>(),
+        56 - if cfg!(feature = "no_position") {
+            WORD_SIZE
+        } else {
+            0
+        }
+    );
 }