diff --git a/sdk_container/src/third_party/portage-stable/eclass/guile-utils.eclass b/sdk_container/src/third_party/portage-stable/eclass/guile-utils.eclass
index b0660dcfd1..d066013486 100644
--- a/sdk_container/src/third_party/portage-stable/eclass/guile-utils.eclass
+++ b/sdk_container/src/third_party/portage-stable/eclass/guile-utils.eclass
@@ -84,10 +84,14 @@ guile_check_compat
 # @FUNCTION: guile_set_common_vars
 # @DESCRIPTION:
 # Sets common variables that apply to all Guile packages, namely,
-# QA_PREBUILT.
+# GUILE_AUTO_COMPILE and QA_PREBUILT.
 guile_set_common_vars() {
 	debug-print-function ${FUNCNAME} "$@"
 
+	# We don't want Guile making decisions based on the system cache
+	# files. Always recompile so we're deterministic.
+	export GUILE_AUTO_COMPILE=fresh
+
 	# These aren't strictly speaking prebuilt. but they do generated a
 	# nonstandard ELF object.
 	if [[ -z ${QA_PREBUILT} ]]; then