diff --git a/ant-antlr.spec b/ant-antlr.spec
index 422b8fc..deafa51 100644
--- a/ant-antlr.spec
+++ b/ant-antlr.spec
@@ -394,6 +394,7 @@ rm -rf build/lib/ant-jai.jar build/lib/ant-netrexx.jar
 export GC_MAXIMUM_HEAP_SIZE="134217728" #128M
 export JAVA_HOME="%{java_home}"
 export CLASSPATH="$JAVA_HOME/lib/tools.jar"
+export BOOTJAVAC_OPTS="-source 1.5 -target 1.5"
 sh -x ./build.sh --noconfig jars
 
 %endif
diff --git a/ant-junit.spec b/ant-junit.spec
index c4d92a8..fb52e06 100644
--- a/ant-junit.spec
+++ b/ant-junit.spec
@@ -394,6 +394,7 @@ rm -rf build/lib/ant-jai.jar build/lib/ant-netrexx.jar
 export GC_MAXIMUM_HEAP_SIZE="134217728" #128M
 export JAVA_HOME="%{java_home}"
 export CLASSPATH="$JAVA_HOME/lib/tools.jar"
+export BOOTJAVAC_OPTS="-source 1.5 -target 1.5"
 sh -x ./build.sh --noconfig jars
 
 %endif
diff --git a/ant.spec b/ant.spec
index 4bcb3c6..0fca4d6 100644
--- a/ant.spec
+++ b/ant.spec
@@ -393,6 +393,7 @@ rm -rf build/lib/ant-jai.jar build/lib/ant-netrexx.jar
 export GC_MAXIMUM_HEAP_SIZE="134217728" #128M
 export JAVA_HOME="%{java_home}"
 export CLASSPATH="$JAVA_HOME/lib/tools.jar"
+export BOOTJAVAC_OPTS="-source 1.5 -target 1.5"
 sh -x ./build.sh --noconfig jars
 
 %endif