diff --git a/config.h b/config.h
index 0f31308adb..10eadf0ac1 100644
--- a/config.h
+++ b/config.h
@@ -47,7 +47,7 @@
 #define  HAVE_XPM            1
 
 /* Use the new XmHTML widdget instead of the old htmlw widget */
-#define HAVE_Z 1               
+#define HAVE_ZLIB 1               
 #define HAVE_PNG 1             
 #define HAVE_JPEG 1            
 
diff --git a/config.h.in b/config.h.in
index 5ae5e57f66..846f1e099a 100644
--- a/config.h.in
+++ b/config.h.in
@@ -46,7 +46,7 @@
 #define  HAVE_XPM            
 
 /* Use the new XmHTML widdget instead of the old htmlw widget */
-#undef HAVE_Z               
+#undef HAVE_ZLIB               
 #undef HAVE_PNG             
 #undef HAVE_JPEG            
 
diff --git a/configure b/configure
index 06fbd05493..7861349872 100755
--- a/configure
+++ b/configure
@@ -1498,7 +1498,7 @@ fi
 if eval "test \"`echo '$ac_cv_lib_'$ac_lib_var`\" = yes"; then
   echo "$ac_t""yes" 1>&6
   cat >> confdefs.h <<\EOF
-#define HAVE_Z 1
+#define HAVE_ZLIB 1
 EOF
  LIBS="-lz $LIBS"
 else
diff --git a/configure.in b/configure.in
index 62f7b4f29a..df67eb0b18 100644
--- a/configure.in
+++ b/configure.in
@@ -45,7 +45,7 @@ AC_SUBST(x_libraries)
 LIBS="-lm"
 
 AC_CHECK_LIB(z, deflateEnd,
-        AC_DEFINE(HAVE_Z,1) LIBS="-lz $LIBS")
+        AC_DEFINE(HAVE_ZLIB,1) LIBS="-lz $LIBS")
 AC_SUBST(LIBS)
 
 AC_CHECK_LIB(jpeg, jpeg_read_scanlines,