diff --git a/src/java/CMakeLists.txt b/src/java/CMakeLists.txt
index fb88781..33ec6af 100644
--- a/src/java/CMakeLists.txt
+++ b/src/java/CMakeLists.txt
@@ -13,7 +13,10 @@ set_source_files_properties (mraajava.i PROPERTIES CPLUSPLUS ON)
 set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fpermissive -DJAVACALLBACK")
 set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DJAVACALLBACK")
 
-if (NOT DEFINED $ENV{JAVA_HOME_NATIVE})
+if (NOT DEFINED ENV{JAVA_HOME_NATIVE})
+  if (NOT DEFINED ENV{JAVA_HOME})
+    message (FATAL_ERROR " - Neither JAVA_HOME nor JAVA_HOME_NATIVE are set")
+  endif()
   set (JAVA_HOME_NATIVE $ENV{JAVA_HOME})
   set (JAVAC $ENV{JAVA_HOME}/bin/javac)
   set (JAR $ENV{JAVA_HOME}/bin/jar)