diff --git a/src/eval/global_state.rs b/src/eval/global_state.rs
index 1144b851..98e39870 100644
--- a/src/eval/global_state.rs
+++ b/src/eval/global_state.rs
@@ -23,12 +23,9 @@ pub type GlobalConstants =
 // corresponds to that key.
 #[derive(Clone)]
 pub struct GlobalRuntimeState<'a> {
-    /// Stack of module names.
-    #[cfg(not(feature = "no_module"))]
-    keys: crate::StaticVec<crate::ImmutableString>,
     /// Stack of imported [modules][crate::Module].
     #[cfg(not(feature = "no_module"))]
-    modules: crate::StaticVec<crate::Shared<crate::Module>>,
+    modules: crate::StaticVec<(crate::ImmutableString, crate::Shared<crate::Module>)>,
     /// Source of the current context.
     ///
     /// No source if the string is empty.
@@ -80,8 +77,6 @@ impl GlobalRuntimeState<'_> {
     #[must_use]
     pub fn new(engine: &Engine) -> Self {
         Self {
-            #[cfg(not(feature = "no_module"))]
-            keys: crate::StaticVec::new_const(),
             #[cfg(not(feature = "no_module"))]
             modules: crate::StaticVec::new_const(),
             source: Identifier::new_const(),
@@ -123,7 +118,7 @@ impl GlobalRuntimeState<'_> {
     #[inline(always)]
     #[must_use]
     pub fn num_imports(&self) -> usize {
-        self.keys.len()
+        self.modules.len()
     }
     /// Get the globally-imported [module][crate::Module] at a particular index.
     ///
@@ -132,7 +127,7 @@ impl GlobalRuntimeState<'_> {
     #[inline(always)]
     #[must_use]
     pub fn get_shared_import(&self, index: usize) -> Option<crate::Shared<crate::Module>> {
-        self.modules.get(index).cloned()
+        self.modules.get(index).map(|(_, m)| m).cloned()
     }
     /// Get a mutable reference to the globally-imported [module][crate::Module] at a
     /// particular index.
@@ -146,7 +141,7 @@ impl GlobalRuntimeState<'_> {
         &mut self,
         index: usize,
     ) -> Option<&mut crate::Shared<crate::Module>> {
-        self.modules.get_mut(index)
+        self.modules.get_mut(index).map(|(_, m)| m)
     }
     /// Get the index of a globally-imported [module][crate::Module] by name.
     ///
@@ -155,12 +150,12 @@ impl GlobalRuntimeState<'_> {
     #[inline]
     #[must_use]
     pub fn find_import(&self, name: &str) -> Option<usize> {
-        let len = self.keys.len();
+        let len = self.modules.len();
 
-        self.keys
+        self.modules
             .iter()
             .rev()
-            .position(|key| key.as_str() == name)
+            .position(|(key, _)| key.as_str() == name)
             .map(|i| len - 1 - i)
     }
     /// Push an imported [module][crate::Module] onto the stack.
@@ -173,8 +168,7 @@ impl GlobalRuntimeState<'_> {
         name: impl Into<crate::ImmutableString>,
         module: impl Into<crate::Shared<crate::Module>>,
     ) {
-        self.keys.push(name.into());
-        self.modules.push(module.into());
+        self.modules.push((name.into(), module.into()));
     }
     /// Truncate the stack of globally-imported [modules][crate::Module] to a particular length.
     ///
@@ -182,7 +176,6 @@ impl GlobalRuntimeState<'_> {
     #[cfg(not(feature = "no_module"))]
     #[inline(always)]
     pub fn truncate_imports(&mut self, size: usize) {
-        self.keys.truncate(size);
         self.modules.truncate(size);
     }
     /// Get an iterator to the stack of globally-imported [modules][crate::Module] in reverse order.
@@ -192,10 +185,9 @@ impl GlobalRuntimeState<'_> {
     #[allow(dead_code)]
     #[inline]
     pub fn iter_imports(&self) -> impl Iterator<Item = (&str, &crate::Module)> {
-        self.keys
+        self.modules
             .iter()
             .rev()
-            .zip(self.modules.iter().rev())
             .map(|(name, module)| (name.as_str(), &**module))
     }
     /// Get an iterator to the stack of globally-imported [modules][crate::Module] in reverse order.
@@ -206,8 +198,8 @@ impl GlobalRuntimeState<'_> {
     #[inline]
     pub(crate) fn iter_imports_raw(
         &self,
-    ) -> impl Iterator<Item = (&crate::ImmutableString, &crate::Shared<crate::Module>)> {
-        self.keys.iter().rev().zip(self.modules.iter().rev())
+    ) -> impl Iterator<Item = &(crate::ImmutableString, crate::Shared<crate::Module>)> {
+        self.modules.iter().rev()
     }
     /// Get an iterator to the stack of globally-imported [modules][crate::Module] in forward order.
     ///
@@ -217,8 +209,8 @@ impl GlobalRuntimeState<'_> {
     #[inline]
     pub fn scan_imports_raw(
         &self,
-    ) -> impl Iterator<Item = (&crate::ImmutableString, &crate::Shared<crate::Module>)> {
-        self.keys.iter().zip(self.modules.iter())
+    ) -> impl Iterator<Item = &(crate::ImmutableString, crate::Shared<crate::Module>)> {
+        self.modules.iter()
     }
     /// Does the specified function hash key exist in the stack of globally-imported
     /// [modules][crate::Module]?
@@ -229,7 +221,9 @@ impl GlobalRuntimeState<'_> {
     #[inline]
     #[must_use]
     pub fn contains_qualified_fn(&self, hash: u64) -> bool {
-        self.modules.iter().any(|m| m.contains_qualified_fn(hash))
+        self.modules
+            .iter()
+            .any(|(_, m)| m.contains_qualified_fn(hash))
     }
     /// Get the specified function via its hash key from the stack of globally-imported
     /// [modules][crate::Module].
@@ -245,7 +239,7 @@ impl GlobalRuntimeState<'_> {
         self.modules
             .iter()
             .rev()
-            .find_map(|m| m.get_qualified_fn(hash).map(|f| (f, m.id())))
+            .find_map(|(_, m)| m.get_qualified_fn(hash).map(|f| (f, m.id())))
     }
     /// Does the specified [`TypeId`][std::any::TypeId] iterator exist in the stack of
     /// globally-imported [modules][crate::Module]?
@@ -256,7 +250,9 @@ impl GlobalRuntimeState<'_> {
     #[inline]
     #[must_use]
     pub fn contains_iter(&self, id: std::any::TypeId) -> bool {
-        self.modules.iter().any(|m| m.contains_qualified_iter(id))
+        self.modules
+            .iter()
+            .any(|(_, m)| m.contains_qualified_iter(id))
     }
     /// Get the specified [`TypeId`][std::any::TypeId] iterator from the stack of globally-imported
     /// [modules][crate::Module].
@@ -269,7 +265,7 @@ impl GlobalRuntimeState<'_> {
         self.modules
             .iter()
             .rev()
-            .find_map(|m| m.get_qualified_iter(id))
+            .find_map(|(_, m)| m.get_qualified_iter(id))
     }
     /// Get the current source.
     #[inline]
@@ -312,29 +308,26 @@ impl GlobalRuntimeState<'_> {
 #[cfg(not(feature = "no_module"))]
 impl IntoIterator for GlobalRuntimeState<'_> {
     type Item = (crate::ImmutableString, crate::Shared<crate::Module>);
-    type IntoIter = std::iter::Zip<
-        std::iter::Rev<smallvec::IntoIter<[crate::ImmutableString; 3]>>,
-        std::iter::Rev<smallvec::IntoIter<[crate::Shared<crate::Module>; 3]>>,
+    type IntoIter = std::iter::Rev<
+        smallvec::IntoIter<
+            [(crate::ImmutableString, crate::Shared<crate::Module>); crate::STATIC_VEC_INLINE_SIZE],
+        >,
     >;
 
     fn into_iter(self) -> Self::IntoIter {
-        self.keys
-            .into_iter()
-            .rev()
-            .zip(self.modules.into_iter().rev())
+        self.modules.into_iter().rev()
     }
 }
 
 #[cfg(not(feature = "no_module"))]
 impl<'a> IntoIterator for &'a GlobalRuntimeState<'_> {
-    type Item = (&'a crate::ImmutableString, &'a crate::Shared<crate::Module>);
-    type IntoIter = std::iter::Zip<
-        std::iter::Rev<std::slice::Iter<'a, crate::ImmutableString>>,
-        std::iter::Rev<std::slice::Iter<'a, crate::Shared<crate::Module>>>,
+    type Item = &'a (crate::ImmutableString, crate::Shared<crate::Module>);
+    type IntoIter = std::iter::Rev<
+        std::slice::Iter<'a, (crate::ImmutableString, crate::Shared<crate::Module>)>,
     >;
 
     fn into_iter(self) -> Self::IntoIter {
-        self.keys.iter().rev().zip(self.modules.iter().rev())
+        self.modules.iter().rev()
     }
 }
 
@@ -345,8 +338,7 @@ impl<K: Into<crate::ImmutableString>, M: Into<crate::Shared<crate::Module>>> Ext
     #[inline]
     fn extend<T: IntoIterator<Item = (K, M)>>(&mut self, iter: T) {
         for (k, m) in iter {
-            self.keys.push(k.into());
-            self.modules.push(m.into());
+            self.modules.push((k.into(), m.into()));
         }
     }
 }
@@ -358,7 +350,7 @@ impl fmt::Debug for GlobalRuntimeState<'_> {
         let mut f = f.debug_struct("GlobalRuntimeState");
 
         #[cfg(not(feature = "no_module"))]
-        f.field("imports", &self.keys.iter().zip(self.modules.iter()));
+        f.field("imports", &self.modules);
 
         f.field("source", &self.source)
             .field("num_operations", &self.num_operations);
diff --git a/src/func/native.rs b/src/func/native.rs
index f421c262..490fba30 100644
--- a/src/func/native.rs
+++ b/src/func/native.rs
@@ -235,7 +235,7 @@ impl<'a> NativeCallContext<'a> {
     #[inline]
     pub(crate) fn iter_imports_raw(
         &self,
-    ) -> impl Iterator<Item = (&crate::ImmutableString, &Shared<Module>)> {
+    ) -> impl Iterator<Item = &(crate::ImmutableString, Shared<Module>)> {
         self.global.iter().flat_map(|&g| g.iter_imports_raw())
     }
     /// _(internals)_ The current [`GlobalRuntimeState`], if any.