diff --git a/lib/generics/unify.js b/lib/generics/unify.js
index 8dcff8f..dde60fc 100644
--- a/lib/generics/unify.js
+++ b/lib/generics/unify.js
@@ -157,7 +157,7 @@ export const unify = (typeA, typeB) => {
 
     // A and B are not typevars
     if (typeA.symbol !== typeB.symbol) {
-      throw new IncompabibleTypesError(typeA, typeB);
+      throw new IncompatibleTypesError(typeA, typeB);
     }
 
     const subs = zip(typeA.params, typeB.params)
@@ -171,11 +171,11 @@ export const unify = (typeA, typeB) => {
   }
   catch (e) {
     if (e instanceof SubstitutionCycle) {
-      throw new IncompabibleTypesError(typeA, typeB, e);
+      throw new IncompatibleTypesError(typeA, typeB, e);
     }
-    if (e instanceof IncompabibleTypesError) {
+    if (e instanceof IncompatibleTypesError) {
       // nest errors to get a nice trace of what went wrong
-      throw new IncompabibleTypesError(typeA, typeB, e);
+      throw new IncompatibleTypesError(typeA, typeB, e);
     }
     throw e;
   }
diff --git a/tests/unify.js b/tests/unify.js
index 588de70..cb72f8e 100644
--- a/tests/unify.js
+++ b/tests/unify.js
@@ -1,7 +1,7 @@
 import assert from "node:assert";
 
 import { getDefaultTypeParser } from "../lib/parser/type_parser.js";
-import { IncompabibleTypesError, subsitutionsEqual, unify } from "../lib/generics/unify.js";
+import { IncompatibleTypesError, subsitutionsEqual, unify } from "../lib/generics/unify.js";
 
 
 const assertSubsitutionsEqual = (m1,m2) => {
@@ -27,7 +27,7 @@ assert.throws(
       mkType("Bool")
     );
   },
-  IncompabibleTypesError,
+  IncompatibleTypesError,
 );
 
 assertSubsitutionsEqual(
@@ -69,7 +69,7 @@ assert.throws(
       mkType("[b] -> b"),    
     );
   },
-  IncompabibleTypesError,
+  IncompatibleTypesError,
 );
 
 assertSubsitutionsEqual(
@@ -90,7 +90,7 @@ assert.throws(
       mkType("b -> (c -> b)"),
     );
   },
-  IncompabibleTypesError,
+  IncompatibleTypesError,
   // String,
 );