diff --git a/guix/build/ant-build-system.scm b/guix/build/ant-build-system.scm
index fae1b47ec5..d29912bf59 100644
--- a/guix/build/ant-build-system.scm
+++ b/guix/build/ant-build-system.scm
@@ -19,7 +19,6 @@
 
 (define-module (guix build ant-build-system)
   #:use-module ((guix build gnu-build-system) #:prefix gnu:)
-  #:use-module (guix build syscalls)
   #:use-module (guix build utils)
   #:use-module (sxml simple)
   #:use-module (ice-9 match)
@@ -201,7 +200,7 @@ dependencies of this jar file."
 repack them.  This is necessary to ensure that archives are reproducible."
   (define (repack-archive jar)
     (format #t "repacking ~a\n" jar)
-    (let* ((dir (mkdtemp! "jar-contents.XXXXXX"))
+    (let* ((dir (mkdtemp "jar-contents.XXXXXX"))
            (manifest (string-append dir "/META-INF/MANIFEST.MF")))
       (with-directory-excursion dir
         (invoke "jar" "xf" jar))
diff --git a/guix/build/java-utils.scm b/guix/build/java-utils.scm
index 87c3ac43c9..6025c81667 100644
--- a/guix/build/java-utils.scm
+++ b/guix/build/java-utils.scm
@@ -21,7 +21,6 @@
 
 (define-module (guix build java-utils)
   #:use-module (guix build utils)
-  #:use-module (guix build syscalls)
   #:use-module (guix build maven pom)
   #:use-module (guix build maven plugin)
   #:use-module (ice-9 match)
@@ -83,7 +82,7 @@ fetched."
   "Unpack the jar archive, add the pom file, and repack it.  This is necessary
 to ensure that maven can find dependencies."
   (format #t "adding ~a to ~a\n" pom-file jar)
-  (let* ((dir (mkdtemp! "jar-contents.XXXXXX"))
+  (let* ((dir (mkdtemp "jar-contents.XXXXXX"))
          (manifest (string-append dir "/META-INF/MANIFEST.MF"))
          (pom (get-pom pom-file))
          (artifact (pom-artifactid pom))