diff --git a/Makefile b/Makefile
index 11d3b13..28f9943 100644
--- a/Makefile
+++ b/Makefile
@@ -6,8 +6,6 @@ SRC_DIR := src
 
 RES_DIR := res
 
-PHEADERS = $(HEADERS):$(JAVA_HOME)/jre/lib/rt.jar
-
 rwildcard=$(wildcard $1$2) $(foreach d,$(wildcard $1*),$(call rwildcard,$d/,$2))
 
 SRCS := $(call rwildcard,$(SRC_DIR),*.kt)
@@ -31,11 +29,11 @@ clean:
 	rm -rf jars/
 
 jars/result.jar: jars/classes.jar
-	proguard -include proguard.conf -libraryjars $(PHEADERS) -keepclassmembers class $(CLASSNAME) { public \<methods\> ';' } -keep public class $(CLASSNAME)
+	proguard -include proguard.conf -libraryjars $(HEADERS) -keepclassmembers class $(CLASSNAME) { public \<methods\> ';' } -keep public class $(CLASSNAME)
 
 release jars/release.jar: jars/result.jar
 	-$(RETROTRANSLATOR) -srcjar jars/result.jar -destjar jars/release.jar
-	jar -umf META-INF/MANIFEST.MF jars/release.jar -C res .
+	$(JAVA_HOME)/bin/jar -umf META-INF/MANIFEST.MF jars/release.jar -C res .
 
 run:
 	$(EMULATOR) jars/release.jar