diff --git a/README.md b/README.md
index 0754073..ded5e67 100644
--- a/README.md
+++ b/README.md
@@ -86,10 +86,19 @@
 
 ## Installation
 
+Koral requires Java 1.7 particularly to compile
+Cosmas2 ANTLR grammars. In pom.xml, specify the javac location of your Java 1.7
+in the ```<java1.7>``` property. By default it set to ```/usr/local/java/jdk1.7.0_79```.
+
+	<properties>
+		<java1.7>/usr/local/java/jdk1.7.0_79</java1.7>
+	</properties>
+
 Installation is straightforward (Maven3 required):
 
     git clone https://github.com/korap/Koral [install-dir]
     cd [install-dir]
+    mvn compile
     mvn test -Dhttps.protocols=TLSv1.2
     mvn install
 
diff --git a/pom.xml b/pom.xml
index 8149525..80804d9 100644
--- a/pom.xml
+++ b/pom.xml
@@ -37,6 +37,7 @@
 	<properties>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>		
 		<jackson.version>2.9.1</jackson.version>
+		<java1.7>/usr/local/java/jdk1.7.0_79</java1.7>
 	</properties>
 	
 	<repositories>
@@ -180,6 +181,9 @@
 				<artifactId>maven-compiler-plugin</artifactId>
 				<version>3.3</version>
 				<configuration>
+					<verbose>true</verbose>
+		          	<fork>true</fork>
+		         	<executable>${java1.7}/bin/javac</executable>
 					<compilerVersion>1.7</compilerVersion>
 					<source>1.7</source>
 					<target>1.7</target>