diff --git a/compiler/solve/src/solve.rs b/compiler/solve/src/solve.rs
index 295ce253d3..0fbb9cf689 100644
--- a/compiler/solve/src/solve.rs
+++ b/compiler/solve/src/solve.rs
@@ -3028,13 +3028,7 @@ fn deep_copy_var_in(
     // we have tracked all visited variables, and can now traverse them
     // in one go (without looking at the UnificationTable) and clear the copy field
     for var in visited {
-        subs.modify(var, |descriptor| {
-            if descriptor.copy.is_some() {
-                descriptor.rank = Rank::NONE;
-                descriptor.mark = Mark::NONE;
-                descriptor.copy = OptVariable::NONE;
-            }
-        });
+        subs.set_copy_unchecked(var, OptVariable::NONE);
     }
 
     copy
@@ -3198,7 +3192,7 @@ fn deep_copy_var_help(
                 }
             };
 
-            subs.set(copy, make_descriptor(Structure(new_flat_type)));
+            subs.set_content_unchecked(copy, Structure(new_flat_type));
 
             copy
         }
@@ -3211,25 +3205,24 @@ fn deep_copy_var_help(
         } => {
             let new_structure = deep_copy_var_help(subs, max_rank, pools, visited, structure);
 
-            subs.set(
-                copy,
-                make_descriptor(RecursionVar {
-                    opt_name,
-                    structure: new_structure,
-                }),
-            );
+            let content = RecursionVar {
+                opt_name,
+                structure: new_structure,
+            };
+
+            subs.set_content_unchecked(copy, content);
 
             copy
         }
 
         RigidVar(name) => {
-            subs.set(copy, make_descriptor(FlexVar(Some(name))));
+            subs.set_content_unchecked(copy, FlexVar(Some(name)));
 
             copy
         }
 
         RigidAbleVar(name, ability) => {
-            subs.set(copy, make_descriptor(FlexAbleVar(Some(name), ability)));
+            subs.set_content_unchecked(copy, FlexAbleVar(Some(name), ability));
 
             copy
         }
@@ -3247,7 +3240,7 @@ fn deep_copy_var_help(
                 deep_copy_var_help(subs, max_rank, pools, visited, real_type_var);
             let new_content = Alias(symbol, new_arguments, new_real_type_var, kind);
 
-            subs.set(copy, make_descriptor(new_content));
+            subs.set_content_unchecked(copy, new_content);
 
             copy
         }
@@ -3259,7 +3252,7 @@ fn deep_copy_var_help(
 
             let new_content = RangedNumber(new_type_var, new_variables);
 
-            subs.set(copy, make_descriptor(new_content));
+            subs.set_content_unchecked(copy, new_content);
 
             copy
         }
diff --git a/compiler/types/src/subs.rs b/compiler/types/src/subs.rs
index a65e8c8846..da17f69d44 100644
--- a/compiler/types/src/subs.rs
+++ b/compiler/types/src/subs.rs
@@ -1720,11 +1720,13 @@ impl Subs {
     }
 
     pub fn set_content(&mut self, key: Variable, content: Content) {
-        // let l_key = self.utable.inlined_get_root_key(key);
-
         self.utable.set_content(key, content);
     }
 
+    pub fn set_content_unchecked(&mut self, key: Variable, content: Content) {
+        self.utable.set_content_unchecked(key, content);
+    }
+
     pub fn modify<F, T>(&mut self, key: Variable, mapper: F) -> T
     where
         F: FnOnce(&mut Descriptor) -> T,