diff --git a/configure.in b/configure.in
index 7874967cc333..cfeca95d3c39 100644
--- a/configure.in
+++ b/configure.in
@@ -770,8 +770,7 @@ dnl the qsort routine under solaris is faulty
        _WARNINGS_CFLAGS=''
        _WARNINGS_CXXFLAGS=''
        if test "$OS_RELEASE" = "5.3"; then
-	  dnl So jmorecfg.h won't redefine boolean.
-	  AC_DEFINE(HAVE_BOOLEAN)
+	  AC_DEFINE(MUST_UNDEF_HAVE_BOOLEAN_AFTER_INCLUDES)
        fi
     fi
     ;;
diff --git a/jpeg/jmorecfg.h b/jpeg/jmorecfg.h
index 3a52fc2204fd..3d0fe1e7efc6 100644
--- a/jpeg/jmorecfg.h
+++ b/jpeg/jmorecfg.h
@@ -252,6 +252,13 @@ typedef unsigned int JDIMENSION;
  * than fight.
  */
 
+/* For some reason, on SunOS 5.3 HAVE_BOOLEAN gets defined when using
+ * gcc, but boolean doesn't.  Even if you use -UHAVE_BOOLEAN, it still
+ * gets reset somewhere.
+ */
+#if defined(MUST_UNDEF_HAVE_BOOLEAN_AFTER_INCLUDES) && defined(HAVE_BOOLEAN)
+#undef HAVE_BOOLEAN
+#endif
 #ifndef HAVE_BOOLEAN
 typedef unsigned char boolean;
 #endif