diff --git a/Makefile b/Makefile
index c9f47d98150e2d47ebe172ccc96337e0b2efdc30..10febce5af4e1f269f0b432a72ed294b0d4b63c9 100644
--- a/Makefile
+++ b/Makefile
@@ -1,30 +1,32 @@
 #!/bin/bash
 # Andreas Romeyke, SLUB Dresden
+# Plugin, welches Matroska/FFv1 via mediaconch validiert
 
 # Pfad zu Java
 JAVAPATH=/usr/lib/jvm/java-1.17.0-openjdk-*/bin/
 JAVARELEASE=17
+
 # Verwendete Rosetta-Version
-ROSETTAVERSION=7.3.0
+ROSETTAVERSION:=7.3.0
 
 # Pfad zum Rosetta-SDK
 ROSETTASDK=/exlibris/dps/d4_1/system.dir/dps-sdk-${ROSETTAVERSION}/lib/
 # Pfad zum Rosetta-SDK, Deposit-Module
-ROSETTASDKDEPOSIT=${ROSETTASDK}/../dps-sdk-projects/dps-sdk-deposit/lib
-ROSETTASDKPLUGINS=${ROSETTASDK}/../../bundled_plugins/
+ROSETTASDKDEPOSIT:=${ROSETTASDK}/../dps-sdk-projects/dps-sdk-deposit/lib
+ROSETTASDKPLUGINS:=${ROSETTASDK}/../../bundled_plugins/
 
 
 # classpath
-JUNITCLASSPATH=/usr/share/java/junit4.jar
+JUNITCLASSPATH:=/usr/share/java/junit4.jar
 #SOURCESCLASSPATH=org/slub/rosetta/dps/repository/plugin/storage/nfs
-CLASSPATH=${ROSETTASDKDEPOSIT}/dps-sdk-${ROSETTAVERSION}.jar
+CLASSPATH:=${ROSETTASDKDEPOSIT}/dps-sdk-${ROSETTAVERSION}.jar
 #BUILDPATH=$(CLASSPATH)
 
 # sources
-SOURCES=java/org/slub/rosetta/dps/repository/plugin/SLUBMatroskaFFV1FormatValidationPlugin.java
-OBJS=$(SOURCES:.java=.class)
-JAR=SLUBMatroskaFFV1FormatValidationPlugin.jar
-BUILD=build/
+SOURCES:=java/org/slub/rosetta/dps/repository/plugin/SLUBMatroskaFFV1FormatValidationPlugin.java
+OBJS:=$(SOURCES:.java=.class)
+JAR:=SLUBMatroskaFFV1FormatValidationPlugin.jar
+BUILD:=build/
 
 all: $(BUILD) $(JAR)