diff --git a/make/js.mk b/make/js.mk
index d3712281..7bd4fed1 100644
--- a/make/js.mk
+++ b/make/js.mk
@@ -3,12 +3,13 @@ JS_MINIFY_FILTER_IN   ?= sed 's/console\.[a-z]\+([^)]\+) *;//g'
 JS_SRC                ?= $(filter-out %.min.js,$(wildcard *.js))
 JS_GENERATED          ?= $(patsubst %.js,%.min.js,$(JS_SRC))
 JS_EXTRA_EXTERNS      ?=
-JS_EXTERNS_DIRS       ?= /opt/closure-compiler/share/externs
+JS_CC_BUILD_ROOT      ?= $(CVS_PROJ_DIR)/closure-compiler/contrib/closure-compiler/install-root
+JS_EXTERNS_DIRS       ?= $(firstword $(wildcard $(JS_CC_BUILD_ROOT)/$(realpath $(CVS_PROJ_DIR))/closure-compiler/share/externs /opt/closure-compiler/share/externs))
 JS_EXTERNS            ?= $(sort $(JS_EXTRA_EXTERNS) jquery-3.3.js)
 JS_EXTERN_PATHS       ?= $(wildcard $(foreach d,$(JS_EXTERNS_DIRS),$(addprefix $d/,$(JS_EXTERNS))))
 JS_MINIFY_OPTS        ?= $(addprefix --externs ,$(JS_EXTERN_PATHS)) --compilation_level ADVANCED --strict_mode_input
 JS_MINIFY_EXE         ?= $(JAVA) -jar $(firstword $(wildcard \
-	$(CVS_PROJ_DIR)/closure-compiler/contrib/closure-compiler/install-root/usr/share/java/closure-compiler.jar \
+	$(JS_CC_BUILD_ROOT)/usr/share/java/closure-compiler.jar \
 	/usr/share/java/closure-compiler.jar \
 	))
 JS_MINIFY             ?= $(JS_MINIFY_EXE) $(JS_MINIFY_OPTS)