diff --git a/repos/base/etc/tools.conf b/repos/base/etc/tools.conf
index 9dcc9e9a2..c3278835a 100644
--- a/repos/base/etc/tools.conf
+++ b/repos/base/etc/tools.conf
@@ -10,13 +10,18 @@
 #CUSTOM_LD      = ld
 
 #
-# For using a cross-compile tool chain, the names of all
-# binutils and compilers are typically prefixed by the
-# target platform. Instead of defining CUSTOM_* variables
-# individually for each tool, the prefix can be defined
-# via the following variable.
+# For using a cross-compile tool chain, the names of all binutils and compilers
+# are typically prefixed by the target platform. Instead of defining CUSTOM_*
+# variables individually for each tool, the prefix can be defined via the
+# following variable.
 #
-ifeq ($(filter-out $(SPECS),x86),)
+# We handle all architectures that may be specified as SPEC argument to the
+# package build tool.
+#
+ifeq ($(filter-out $(SPECS),x86_32),)
+CROSS_DEV_PREFIX ?= /usr/local/genode-gcc/bin/genode-x86-
+endif
+ifeq ($(filter-out $(SPECS),x86_64),)
 CROSS_DEV_PREFIX ?= /usr/local/genode-gcc/bin/genode-x86-
 endif
 ifeq ($(filter-out $(SPECS),arm),)