diff --git a/configure.ac b/configure.ac
index 73adc925..85858230 100644
--- a/configure.ac
+++ b/configure.ac
@@ -231,30 +231,32 @@ AM_CONDITIONAL([WITH_ARITH_DEC], [test "x$with_arith_dec" != "xno"])
 
 AM_CONDITIONAL([WITH_ARITH], [test "x$with_arith_dec" != "xno" -o "x$with_arith_enc" != "xno"])
 
-BUILDJNILIB=0
-case $host_os in
-  darwin*)
-    DEFAULT_JAVA_CFLAGS=-I/System/Library/Frameworks/JavaVM.framework/Headers
-    BUILDJNILIB=1
-    ;;
-  solaris*)
-    DEFAULT_JAVA_CFLAGS='-I/usr/java/include -I/usr/java/include/solaris'
-    ;;
-  linux*)
-    DEFAULT_JAVA_CFLAGS='-I/usr/java/default/include -I/usr/java/default/include/linux'
-    ;;
-esac
-
 AC_ARG_VAR(JAVA_CFLAGS, [Compiler flags needed to find jni.h (default: -I/System/Library/Frameworks/JavaVM.framework/Headers on OS X, '-I/usr/java/include -I/usr/java/include/solaris' on Solaris, and '-I/usr/java/default/include -I/usr/java/default/include/linux' on Linux)])
-if test "x$JAVA_CFLAGS" = "x"; then
-    JAVA_CFLAGS=$DEFAULT_JAVA_CFLAGS
-fi
 
 AC_MSG_CHECKING([whether to include JNI wrapper in TurboJPEG/OSS])
 AC_ARG_WITH([jni],
     AC_HELP_STRING([--with-jni],[Include JNI wrapper in the TurboJPEG/OSS library]))
+
+BUILDJNILIB=0
 if test "x$with_jni" = "xyes"; then
     AC_MSG_RESULT(yes)
+
+    case $host_os in
+      darwin*)
+        DEFAULT_JAVA_CFLAGS=-I/System/Library/Frameworks/JavaVM.framework/Headers
+        BUILDJNILIB=1
+        ;;
+      solaris*)
+        DEFAULT_JAVA_CFLAGS='-I/usr/java/include -I/usr/java/include/solaris'
+        ;;
+      linux*)
+        DEFAULT_JAVA_CFLAGS='-I/usr/java/default/include -I/usr/java/default/include/linux'
+        ;;
+    esac
+    if test "x$JAVA_CFLAGS" = "x"; then
+        JAVA_CFLAGS=$DEFAULT_JAVA_CFLAGS
+    fi
+
     SAVE_CPPFLAGS=${CPPFLAGS}
     CPPFLAGS="${CPPFLAGS} ${JAVA_CFLAGS}"
     AC_CHECK_HEADERS([jni.h], [DUMMY=1],