diff --git a/qvm.asd b/qvm.asd
index 62d60c65..d1021ff3 100644
--- a/qvm.asd
+++ b/qvm.asd
@@ -17,7 +17,7 @@
                ;; General utilities
                #:alexandria
                ;; Abstract classes
-               #:abstract-classes
+               #:org.tfeb.hax.abstract-classes
                ;; IEEE-754 float parsing
                #:ieee-floats
                ;; Parallelization utilities
diff --git a/src/error/package.lisp b/src/error/package.lisp
index a8b8dbc5..36507dd2 100644
--- a/src/error/package.lisp
+++ b/src/error/package.lisp
@@ -5,7 +5,7 @@
 
 (defpackage #:qvm.error
   (:use #:cl
-        #:abstract-classes
+        #:org.tfeb.hax.abstract-classes
         #:qvm)
   (:import-from #:qvm #:multiprobabilistically)
   (:local-nicknames (#:quil     #:cl-quil.frontend))
diff --git a/src/package.lisp b/src/package.lisp
index d0643538..8a924de8 100644
--- a/src/package.lisp
+++ b/src/package.lisp
@@ -5,7 +5,7 @@
 (defpackage #:qvm
   (:documentation "Package containing an implementation of a quantum virtual machine.")
   (:use #:cl
-        #:abstract-classes)
+        #:org.tfeb.hax.abstract-classes)
 
   (:shadowing-import-from #:mt19937
                           #:random)