diff --git a/Makefile.am b/Makefile.am
index 2b9fd9c..82e2247 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -130,7 +130,14 @@ TESTS += \
 	tests/concurrent-web-server.scm
 endif
 
-TESTS_ENVIRONMENT=top_srcdir="$(abs_top_srcdir)" ./env $(GUILE) -s
+# Tests are calibrated to be compiled (they're much slower when
+# interpreted) so make sure they can be auto-compiled upon 'make
+# check'.
+TESTS_ENVIRONMENT =				\
+  top_srcdir="$(abs_top_srcdir)"		\
+  XDG_CACHE_HOME="$(abs_top_builddir)/tests"	\
+  GUILE_AUTO_COMPILE=1				\
+  "$(top_builddir)/env" $(GUILE) -s
 
 EXTRA_DIST += \
 	$(bin_SCRIPTS) \
diff --git a/build-aux/guile.am b/build-aux/guile.am
index 5e94c96..ef656ae 100644
--- a/build-aux/guile.am
+++ b/build-aux/guile.am
@@ -23,6 +23,6 @@ EXTRA_DIST = $(SOURCES) $(NOCOMP_SOURCES)
 GUILE_WARNINGS = -Wunbound-variable -Warity-mismatch -Wformat
 SUFFIXES = .scm .go
 .scm.go:
-	$(AM_V_GEN) $(top_builddir)/env	\
+	$(AM_V_GEN) GUILE_AUTO_COMPILE=0 $(top_builddir)/env		\
 	  $(GUILE_TOOLS) compile $(GUILE_TARGET) -L "$(abs_top_srcdir)"	\
 	  $(GUILE_WARNINGS) -o "$@" "$<"
diff --git a/guix.scm b/guix.scm
index 254eeaa..07dc954 100644
--- a/guix.scm
+++ b/guix.scm
@@ -45,14 +45,6 @@
                       "texinfo" "gettext-minimal"))))
     (inputs
      (list (S "guile")))
-    (arguments
-     `(#:phases (modify-phases %standard-phases
-                  (add-before 'configure 'bootstrap
-                    (lambda _
-                      (zero? (system* "./autogen.sh"))))
-                  (add-before 'configure 'setenv
-                    (lambda _
-                      (setenv "GUILE_AUTO_COMPILE" "0"))))))
     (synopsis "Lightweight concurrency facility for Guile")
     (description
      "Fibers is a Guile library that implements a a lightweight concurrency