diff --git a/src/args.rs b/src/args.rs
index a9f702a..4dc1e97 100644
--- a/src/args.rs
+++ b/src/args.rs
@@ -1,8 +1,9 @@
 use std::collections::BTreeMap;
 use std::iter::Peekable;
 
-use crate::common::{Scope, Symbol};
+use crate::common::Symbol;
 use crate::error::SassResult;
+use crate::scope::Scope;
 use crate::selector::Selector;
 use crate::utils::{devour_whitespace, devour_whitespace_or_comment};
 use crate::value::Value;
diff --git a/src/atrule/mod.rs b/src/atrule/mod.rs
index 4b56be9..31b0724 100644
--- a/src/atrule/mod.rs
+++ b/src/atrule/mod.rs
@@ -3,10 +3,11 @@ use std::iter::Peekable;
 
 use num_traits::cast::ToPrimitive;
 
-use crate::common::{Keyword, Pos, Scope, Symbol};
+use crate::common::{Keyword, Pos, Symbol};
 use crate::error::SassResult;
 use crate::function::Function;
 use crate::mixin::Mixin;
+use crate::scope::Scope;
 use crate::selector::Selector;
 use crate::units::Unit;
 use crate::utils::{devour_whitespace, devour_whitespace_or_comment};
diff --git a/src/atrule/parse.rs b/src/atrule/parse.rs
index 1fd03d4..af88976 100644
--- a/src/atrule/parse.rs
+++ b/src/atrule/parse.rs
@@ -1,7 +1,7 @@
 use std::iter::Peekable;
 
-use crate::common::Scope;
 use crate::error::SassResult;
+use crate::scope::Scope;
 use crate::selector::Selector;
 use crate::{eat_expr, Expr, RuleSet, Stmt, Token};
 
diff --git a/src/atrule/unknown.rs b/src/atrule/unknown.rs
index f398c08..8d54eeb 100644
--- a/src/atrule/unknown.rs
+++ b/src/atrule/unknown.rs
@@ -1,8 +1,9 @@
 use std::iter::Peekable;
 
 use super::parse::eat_stmts;
-use crate::common::{Scope, Symbol};
+use crate::common::Symbol;
 use crate::error::SassResult;
+use crate::scope::Scope;
 use crate::selector::Selector;
 use crate::utils::{devour_whitespace, parse_interpolation};
 use crate::{RuleSet, Stmt, Token, TokenKind};
diff --git a/src/builtin/mod.rs b/src/builtin/mod.rs
index 91e748b..7eaee7d 100644
--- a/src/builtin/mod.rs
+++ b/src/builtin/mod.rs
@@ -2,8 +2,8 @@ use once_cell::sync::Lazy;
 use std::collections::HashMap;
 
 use crate::args::CallArgs;
-use crate::common::Scope;
 use crate::error::SassResult;
+use crate::scope::Scope;
 use crate::value::Value;
 
 #[macro_use]
diff --git a/src/common.rs b/src/common.rs
index a9827e3..d7c5e25 100644
--- a/src/common.rs
+++ b/src/common.rs
@@ -1,12 +1,6 @@
-use std::collections::HashMap;
 use std::convert::TryFrom;
 use std::fmt::{self, Display};
 
-use crate::error::SassResult;
-use crate::function::Function;
-use crate::mixin::Mixin;
-use crate::value::Value;
-
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 pub enum Symbol {
     /// .
@@ -220,6 +214,7 @@ pub enum Keyword {
     False,
     Null,
     Default,
+    Global,
     From(String),
     To(String),
     Through(String),
@@ -243,7 +238,7 @@ impl Display for Keyword {
             Self::False => write!(f, "false"),
             Self::Null => write!(f, "null"),
             Self::Default => write!(f, "!default"),
-            // todo!(maintain casing for keywords)
+            Self::Global => write!(f, "!global"),
             Self::From(s) => write!(f, "{}", s),
             Self::To(s) => write!(f, "{}", s),
             Self::Through(s) => write!(f, "{}", s),
@@ -269,6 +264,7 @@ impl Into<&'static str> for Keyword {
             Self::False => "false",
             Self::Null => "null",
             Self::Default => "!default",
+            Self::Global => "!global",
             Self::From(_) => "from",
             Self::To(_) => "to",
             Self::Through(_) => "through",
@@ -296,6 +292,7 @@ impl TryFrom<&str> for Keyword {
             "false" => Ok(Self::False),
             "null" => Ok(Self::Null),
             "default" => Ok(Self::Default),
+            "global" => Ok(Self::Global),
             "from" => Ok(Self::From(kw.to_owned())),
             "to" => Ok(Self::To(kw.to_owned())),
             "through" => Ok(Self::Through(kw.to_owned())),
@@ -353,75 +350,6 @@ impl Display for Pos {
     }
 }
 
-#[derive(Debug, Clone)]
-pub(crate) struct Scope {
-    vars: HashMap<String, Value>,
-    mixins: HashMap<String, Mixin>,
-    functions: HashMap<String, Function>,
-}
-
-impl Scope {
-    #[must_use]
-    pub fn new() -> Self {
-        Self {
-            vars: HashMap::new(),
-            mixins: HashMap::new(),
-            functions: HashMap::new(),
-        }
-    }
-
-    pub fn get_var(&self, v: &str) -> SassResult<&Value> {
-        match self.vars.get(&v.replace('_', "-")) {
-            Some(v) => Ok(v),
-            None => Err("Undefined variable.".into()),
-        }
-    }
-
-    pub fn insert_var(&mut self, s: &str, v: Value) -> SassResult<Option<Value>> {
-        Ok(self.vars.insert(s.replace('_', "-"), v.eval()?))
-    }
-
-    pub fn var_exists(&self, v: &str) -> bool {
-        self.vars.contains_key(&v.replace('_', "-"))
-    }
-
-    pub fn get_mixin(&self, v: &str) -> SassResult<&Mixin> {
-        match self.mixins.get(&v.replace('_', "-")) {
-            Some(v) => Ok(v),
-            None => Err("Undefined mixin.".into()),
-        }
-    }
-
-    pub fn insert_mixin(&mut self, s: &str, v: Mixin) -> Option<Mixin> {
-        self.mixins.insert(s.replace('_', "-"), v)
-    }
-
-    pub fn mixin_exists(&self, v: &str) -> bool {
-        self.mixins.contains_key(&v.replace('_', "-"))
-    }
-
-    pub fn get_fn(&self, v: &str) -> SassResult<&Function> {
-        match self.functions.get(&v.replace('_', "-")) {
-            Some(v) => Ok(v),
-            None => Err("Undefined function.".into()),
-        }
-    }
-
-    pub fn insert_fn(&mut self, s: &str, v: Function) -> Option<Function> {
-        self.functions.insert(s.replace('_', "-"), v)
-    }
-
-    pub fn fn_exists(&self, v: &str) -> bool {
-        self.functions.contains_key(&v.replace('_', "-"))
-    }
-
-    pub fn extend(&mut self, other: Scope) {
-        self.vars.extend(other.vars);
-        self.mixins.extend(other.mixins);
-        self.functions.extend(other.functions);
-    }
-}
-
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
 pub(crate) enum QuoteKind {
     Single,
diff --git a/src/function.rs b/src/function.rs
index 7cbdf72..18845b3 100644
--- a/src/function.rs
+++ b/src/function.rs
@@ -2,8 +2,9 @@ use std::iter::Peekable;
 
 use crate::args::{eat_func_args, CallArgs, FuncArgs};
 use crate::atrule::AtRule;
-use crate::common::{Scope, Symbol};
+use crate::common::Symbol;
 use crate::error::SassResult;
+use crate::scope::Scope;
 use crate::selector::Selector;
 use crate::utils::devour_whitespace;
 use crate::value::Value;
diff --git a/src/imports.rs b/src/imports.rs
index f178728..f625617 100644
--- a/src/imports.rs
+++ b/src/imports.rs
@@ -1,8 +1,8 @@
 use std::ffi::OsStr;
 use std::path::Path;
 
-use crate::common::Scope;
 use crate::error::SassResult;
+use crate::scope::Scope;
 use crate::{Stmt, StyleSheet};
 
 pub(crate) fn import<P: AsRef<Path>>(path: P) -> SassResult<(Vec<Stmt>, Scope)> {
diff --git a/src/lexer.rs b/src/lexer.rs
index ad0b36e..74b07a1 100644
--- a/src/lexer.rs
+++ b/src/lexer.rs
@@ -180,6 +180,11 @@ impl<'a> Lexer<'a> {
                 assert_char!(self, 'e' 'f' 'a' 'u' 'l' 't');
                 TokenKind::Keyword(Keyword::Default)
             }
+            Some('g') | Some('G') => {
+                self.buf.next();
+                assert_char!(self, 'l' 'o' 'b' 'a' 'l');
+                TokenKind::Keyword(Keyword::Global)
+            }
             Some('=') => {
                 self.buf.next();
                 TokenKind::Op(Op::NotEqual)
diff --git a/src/lib.rs b/src/lib.rs
index 0d5a745..6cb39d1 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -85,7 +85,7 @@ use std::iter::{Iterator, Peekable};
 use std::path::Path;
 
 use crate::atrule::{AtRule, AtRuleKind};
-use crate::common::{Keyword, Op, Pos, Scope, Symbol, Whitespace};
+use crate::common::{Keyword, Op, Pos, Symbol, Whitespace};
 use crate::css::Css;
 use crate::error::SassError;
 pub use crate::error::SassResult;
@@ -94,6 +94,7 @@ use crate::function::Function;
 use crate::imports::import;
 use crate::lexer::Lexer;
 use crate::mixin::{eat_include, Mixin};
+use crate::scope::{insert_global_var, Scope, GLOBAL_SCOPE};
 use crate::selector::Selector;
 use crate::style::Style;
 use crate::utils::{devour_whitespace, eat_variable_value, IsComment, IsWhitespace, VariableDecl};
@@ -111,12 +112,18 @@ mod function;
 mod imports;
 mod lexer;
 mod mixin;
+mod scope;
 mod selector;
 mod style;
 mod units;
 mod utils;
 mod value;
 
+pub(crate) fn error<E: Into<String>>(msg: E) -> ! {
+    eprintln!("Error: {}", msg.into());
+    std::process::exit(1);
+}
+
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub(crate) struct Token {
     pos: Pos,
@@ -391,7 +398,7 @@ impl<'a> StyleSheetParser<'a> {
                 | TokenKind::Symbol(Symbol::Mul)
                 | TokenKind::Symbol(Symbol::Percent)
                 | TokenKind::Symbol(Symbol::Period) => rules
-                    .extend(self.eat_rules(&Selector::new(), &mut self.global_scope.clone())?),
+                    .extend(self.eat_rules(&Selector::new(), &mut GLOBAL_SCOPE.with(|s| s.borrow().clone()))?),
                 TokenKind::Whitespace(_) => {
                     self.lexer.next();
                     continue;
@@ -415,11 +422,16 @@ impl<'a> StyleSheetParser<'a> {
                     {
                         self.error(pos, "unexpected variable use at toplevel");
                     }
-                    let VariableDecl { val, default } =
-                        eat_variable_value(&mut self.lexer, &self.global_scope, &Selector::new())?;
-                    if !default || self.global_scope.get_var(&name).is_err() {
-                        self.global_scope.insert_var(&name, val)?;
-                    }
+                    let VariableDecl { val, default, .. } =
+                        eat_variable_value(&mut self.lexer, &GLOBAL_SCOPE.with(|s| s.borrow().clone()), &Selector::new())?;
+                    GLOBAL_SCOPE.with(|s| {
+                        if !default || s.borrow().get_var(&name).is_err() {
+                            match s.borrow_mut().insert_var(&name, val) {
+                                Ok(..) => {},
+                                Err(e) => error(e),
+                            }
+                        }
+                    })
                 }
                 TokenKind::MultilineComment(_) => {
                     let comment = match self
@@ -435,7 +447,7 @@ impl<'a> StyleSheetParser<'a> {
                 }
                 TokenKind::AtRule(AtRuleKind::Include) => rules.extend(eat_include(
                     &mut self.lexer,
-                    &self.global_scope,
+                    &GLOBAL_SCOPE.with(|s| s.borrow().clone()),
                     &Selector::new(),
                 )?),
                 TokenKind::AtRule(AtRuleKind::Import) => {
@@ -479,7 +491,9 @@ impl<'a> StyleSheetParser<'a> {
 
                     let (new_rules, new_scope) = import(file_name)?;
                     rules.extend(new_rules);
-                    self.global_scope.extend(new_scope);
+                    GLOBAL_SCOPE.with(|s| {
+                        s.borrow_mut().extend(new_scope);
+                    });
                 }
                 TokenKind::AtRule(_) => {
                     if let Some(Token {
@@ -487,12 +501,16 @@ impl<'a> StyleSheetParser<'a> {
                         pos,
                     }) = self.lexer.next()
                     {
-                        match AtRule::from_tokens(rule, pos, &mut self.lexer, &mut self.global_scope, &Selector::new())? {
+                        match AtRule::from_tokens(rule, pos, &mut self.lexer, &mut GLOBAL_SCOPE.with(|s| s.borrow().clone()), &Selector::new())? {
                             AtRule::Mixin(name, mixin) => {
-                                self.global_scope.insert_mixin(&name, *mixin);
+                                GLOBAL_SCOPE.with(|s| {
+                                    s.borrow_mut().insert_mixin(&name, *mixin);
+                                });
                             }
                             AtRule::Function(name, func) => {
-                                self.global_scope.insert_fn(&name, *func);
+                                GLOBAL_SCOPE.with(|s| {
+                                    s.borrow_mut().insert_fn(&name, *func);
+                                });
                             }
                             AtRule::Charset => continue,
                             AtRule::Error(pos, message) => self.error(pos, &message),
@@ -518,7 +536,7 @@ impl<'a> StyleSheetParser<'a> {
                 },
             };
         }
-        Ok((rules, self.global_scope))
+        Ok((rules, GLOBAL_SCOPE.with(|s| s.borrow().clone())))
     }
 
     fn eat_rules(&mut self, super_selector: &Selector, scope: &mut Scope) -> SassResult<Vec<Stmt>> {
@@ -556,7 +574,7 @@ impl<'a> StyleSheetParser<'a> {
                 Expr::VariableDecl(name, val) => {
                     if self.scope == 0 {
                         scope.insert_var(&name, *val.clone())?;
-                        self.global_scope.insert_var(&name, *val)?;
+                        insert_global_var(&name, *val)?;
                     } else {
                         scope.insert_var(&name, *val)?;
                     }
@@ -648,9 +666,14 @@ pub(crate) fn eat_expr<I: Iterator<Item = Token>>(
                 {
                     toks.next();
                     devour_whitespace(toks);
-                    let VariableDecl { val, default } =
-                        eat_variable_value(toks, scope, super_selector)?;
-                    if !default || scope.get_var(&name).is_err() {
+                    let VariableDecl {
+                        val,
+                        default,
+                        global,
+                    } = eat_variable_value(toks, scope, super_selector)?;
+                    if global {
+                        insert_global_var(&name, val)?;
+                    } else if !default || scope.get_var(&name).is_err() {
                         return Ok(Some(Expr::VariableDecl(name, Box::new(val))));
                     }
                 } else {
diff --git a/src/mixin.rs b/src/mixin.rs
index 082c2fa..6b0ffcd 100644
--- a/src/mixin.rs
+++ b/src/mixin.rs
@@ -3,8 +3,9 @@ use std::vec::IntoIter;
 
 use crate::args::{eat_call_args, eat_func_args, CallArgs, FuncArgs};
 use crate::atrule::AtRule;
-use crate::common::{Scope, Symbol};
+use crate::common::Symbol;
 use crate::error::{SassError, SassResult};
+use crate::scope::Scope;
 use crate::selector::Selector;
 use crate::utils::devour_whitespace;
 use crate::{eat_expr, Expr, RuleSet, Stmt, Token, TokenKind};
diff --git a/src/scope.rs b/src/scope.rs
new file mode 100644
index 0000000..2ff5975
--- /dev/null
+++ b/src/scope.rs
@@ -0,0 +1,94 @@
+use std::cell::RefCell;
+use std::collections::HashMap;
+
+use crate::error::SassResult;
+use crate::function::Function;
+use crate::mixin::Mixin;
+use crate::value::Value;
+
+thread_local!(pub(crate) static GLOBAL_SCOPE: RefCell<Scope> = RefCell::new(Scope::new()));
+
+pub(crate) fn get_global_var(s: &str) -> SassResult<Value> {
+    GLOBAL_SCOPE.with(|scope| match scope.borrow().vars().get(s) {
+        Some(v) => Ok(v.clone()),
+        None => Err("Undefined variable.".into()),
+    })
+}
+
+pub(crate) fn insert_global_var(s: &str, v: Value) -> SassResult<Option<Value>> {
+    GLOBAL_SCOPE.with(|scope| scope.borrow_mut().insert_var(s, v))
+}
+
+#[derive(Debug, Clone)]
+pub(crate) struct Scope {
+    vars: HashMap<String, Value>,
+    mixins: HashMap<String, Mixin>,
+    functions: HashMap<String, Function>,
+}
+
+impl Scope {
+    #[must_use]
+    pub fn new() -> Self {
+        Self {
+            vars: HashMap::new(),
+            mixins: HashMap::new(),
+            functions: HashMap::new(),
+        }
+    }
+
+    pub fn vars(&self) -> &HashMap<String, Value> {
+        &self.vars
+    }
+
+    pub fn get_var(&self, v: &str) -> SassResult<Value> {
+        let v = &v.replace('_', "-");
+        match self.vars.get(v) {
+            Some(v) => Ok(v.clone()),
+            None => get_global_var(v),
+        }
+    }
+
+    pub fn insert_var(&mut self, s: &str, v: Value) -> SassResult<Option<Value>> {
+        Ok(self.vars.insert(s.replace('_', "-"), v.eval()?))
+    }
+
+    pub fn var_exists(&self, v: &str) -> bool {
+        self.vars.contains_key(&v.replace('_', "-"))
+    }
+
+    pub fn get_mixin(&self, v: &str) -> SassResult<&Mixin> {
+        match self.mixins.get(&v.replace('_', "-")) {
+            Some(v) => Ok(v),
+            None => Err("Undefined mixin.".into()),
+        }
+    }
+
+    pub fn insert_mixin(&mut self, s: &str, v: Mixin) -> Option<Mixin> {
+        self.mixins.insert(s.replace('_', "-"), v)
+    }
+
+    pub fn mixin_exists(&self, v: &str) -> bool {
+        self.mixins.contains_key(&v.replace('_', "-"))
+    }
+
+    pub fn get_fn(&self, v: &str) -> SassResult<&Function> {
+        match self.functions.get(&v.replace('_', "-")) {
+            Some(v) => Ok(v),
+            None => Err("Undefined function.".into()),
+        }
+    }
+
+    pub fn insert_fn(&mut self, s: &str, v: Function) -> Option<Function> {
+        self.functions.insert(s.replace('_', "-"), v)
+    }
+
+    pub fn fn_exists(&self, v: &str) -> bool {
+        self.functions.contains_key(&v.replace('_', "-"))
+    }
+
+    pub fn extend(&mut self, other: Scope) {
+        self.vars.extend(other.vars);
+        self.mixins.extend(other.mixins);
+        self.functions.extend(other.functions);
+    }
+}
diff --git a/src/selector.rs b/src/selector.rs
index b797fc0..c0f9bc0 100644
--- a/src/selector.rs
+++ b/src/selector.rs
@@ -2,9 +2,10 @@ use std::fmt::{self, Display, Write};
 use std::iter::Peekable;
 use std::string::ToString;
 
-use crate::common::{Scope, Symbol, Whitespace};
+use crate::common::{Symbol, Whitespace};
 use crate::error::SassResult;
 use crate::lexer::Lexer;
+use crate::scope::Scope;
 use crate::utils::{
     devour_whitespace, devour_whitespace_or_comment, flatten_ident, parse_interpolation,
     parse_quoted_string, IsWhitespace,
diff --git a/src/style.rs b/src/style.rs
index e92b1da..30821ce 100644
--- a/src/style.rs
+++ b/src/style.rs
@@ -1,8 +1,9 @@
 use std::fmt::{self, Display};
 use std::iter::Peekable;
 
-use crate::common::{Pos, QuoteKind, Scope, Symbol};
+use crate::common::{Pos, QuoteKind, Symbol};
 use crate::error::SassResult;
+use crate::scope::Scope;
 use crate::selector::Selector;
 use crate::utils::{devour_whitespace, parse_interpolation, parse_quoted_string};
 use crate::value::Value;
diff --git a/src/utils.rs b/src/utils.rs
index 50d2d6f..1292065 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -83,11 +83,16 @@ pub(crate) fn parse_interpolation<I: Iterator<Item = Token>>(
 pub(crate) struct VariableDecl {
     pub val: Value,
     pub default: bool,
+    pub global: bool,
 }
 
 impl VariableDecl {
-    pub const fn new(val: Value, default: bool) -> VariableDecl {
-        VariableDecl { val, default }
+    pub const fn new(val: Value, default: bool, global: bool) -> VariableDecl {
+        VariableDecl {
+            val,
+            default,
+            global,
+        }
     }
 }
 
@@ -98,6 +103,7 @@ pub(crate) fn eat_variable_value<I: Iterator<Item = Token>>(
 ) -> SassResult<VariableDecl> {
     devour_whitespace(toks);
     let mut default = false;
+    let mut global = false;
     let mut raw: Vec<Token> = Vec::new();
     let mut nesting = 0;
     while let Some(tok) = toks.peek() {
@@ -110,6 +116,10 @@ pub(crate) fn eat_variable_value<I: Iterator<Item = Token>>(
                 toks.next();
                 default = true
             }
+            TokenKind::Keyword(Keyword::Global) => {
+                toks.next();
+                global = true
+            }
             TokenKind::Interpolation | TokenKind::Symbol(Symbol::OpenCurlyBrace) => {
                 nesting += 1;
                 raw.push(toks.next().unwrap());
@@ -127,7 +137,7 @@ pub(crate) fn eat_variable_value<I: Iterator<Item = Token>>(
     }
     devour_whitespace(toks);
     let val = Value::from_tokens(&mut raw.into_iter().peekable(), scope, super_selector).unwrap();
-    Ok(VariableDecl::new(val, default))
+    Ok(VariableDecl::new(val, default, global))
 }
 
 pub(crate) fn flatten_ident<I: Iterator<Item = Token>>(
diff --git a/src/value/parse.rs b/src/value/parse.rs
index 209cf40..5a4083e 100644
--- a/src/value/parse.rs
+++ b/src/value/parse.rs
@@ -8,8 +8,9 @@ use num_traits::pow;
 use crate::args::eat_call_args;
 use crate::builtin::GLOBAL_FUNCTIONS;
 use crate::color::Color;
-use crate::common::{Keyword, ListSeparator, Op, QuoteKind, Scope, Symbol};
+use crate::common::{Keyword, ListSeparator, Op, QuoteKind, Symbol};
 use crate::error::SassResult;
+use crate::scope::Scope;
 use crate::selector::Selector;
 use crate::units::Unit;
 use crate::utils::{
diff --git a/tests/scope.rs b/tests/scope.rs
new file mode 100644
index 0000000..ba1f8fc
--- /dev/null
+++ b/tests/scope.rs
@@ -0,0 +1,15 @@
+#![cfg(test)]
+
+#[macro_use]
+mod macros;
+
+test!(
+    scoping_var_decl_inner_ruleset,
+    "a {\n  $color: red;\n  b {\n    $color: blue;\n  }\n  color: $color;\n}\n",
+    "a {\n  color: blue;\n}\n"
+);
+test!(
+    basic_global,
+    "a {\n  $color: red !global;\n}\n\nb {\n  color: $color;\n}\n",
+    "b {\n  color: red;\n}\n"
+);