diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e5d92f01ec78..c3b803588e8c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2010-08-12  Joseph Myers  <joseph@codesourcery.com>
+
+	* gcc.c (cpp_unique_options): Generate -MDX and -MMDX from -MD and
+	-MMD.
+
 2010-08-12  Changpeng Fang  <changpeng.fang@amd.com>
 
 	* tree-vect-patterns.c (vect_recog_dot_prod_pattern): Give
diff --git a/gcc/c-family/ChangeLog b/gcc/c-family/ChangeLog
index ce4fa365388b..56aabb456656 100644
--- a/gcc/c-family/ChangeLog
+++ b/gcc/c-family/ChangeLog
@@ -1,3 +1,8 @@
+2010-08-12  Joseph Myers  <joseph@codesourcery.com>
+
+	* c.opt (MD, MMD): Change to MDX and MMDX.
+	* c-opts.c (c_common_handle_option): Use OPT_MMD and OPT_MMDX.
+
 2010-08-11  Joseph Myers  <joseph@codesourcery.com>
 
 	* c-opts.c (c_common_handle_option): Call handle_generated_option
diff --git a/gcc/c-family/c-opts.c b/gcc/c-family/c-opts.c
index b46b0a04908f..cce42651ffe0 100644
--- a/gcc/c-family/c-opts.c
+++ b/gcc/c-family/c-opts.c
@@ -398,9 +398,9 @@ c_common_handle_option (size_t scode, const char *arg, int value,
       flag_no_output = 1;
       break;
 
-    case OPT_MD:
-    case OPT_MMD:
-      cpp_opts->deps.style = (code == OPT_MD ? DEPS_SYSTEM: DEPS_USER);
+    case OPT_MDX:
+    case OPT_MMDX:
+      cpp_opts->deps.style = (code == OPT_MDX ? DEPS_SYSTEM: DEPS_USER);
       cpp_opts->deps.need_preprocessor_output = true;
       deps_file = arg;
       break;
diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
index 0c51766f74e6..98569cbae125 100644
--- a/gcc/c-family/c.opt
+++ b/gcc/c-family/c.opt
@@ -72,9 +72,9 @@ M
 C ObjC C++ ObjC++
 Generate make dependencies
 
-MD
+MDX
 C ObjC C++ ObjC++ Separate MissingArgError(missing filename after %qs)
-Generate make dependencies and compile
+-MD	Generate make dependencies and compile
 
 MF
 C ObjC C++ ObjC++ Joined Separate MissingArgError(missing filename after %qs)
@@ -88,9 +88,9 @@ MM
 C ObjC C++ ObjC++
 Like -M but ignore system header files
 
-MMD
+MMDX
 C ObjC C++ ObjC++ Separate MissingArgError(missing filename after %qs)
-Like -MD but ignore system header files
+-MMD	Like -MD but ignore system header files
 
 MP
 C ObjC C++ ObjC++
diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index e34b6acc91b0..e987159f037f 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,8 @@
+2010-08-12  Joseph Myers  <joseph@codesourcery.com>
+
+	* lang.opt (MD, MMD): Change to MDX and MMDX.
+	* cpp.c (gfc_cpp_handle_option): Use OPT_MMD and OPT_MMDX.
+
 2010-08-11  Janus Weil  <janus@gcc.gnu.org>
 
 	PR fortran/44595
diff --git a/gcc/fortran/cpp.c b/gcc/fortran/cpp.c
index a6a922f0ff91..046a9a27dbd5 100644
--- a/gcc/fortran/cpp.c
+++ b/gcc/fortran/cpp.c
@@ -456,11 +456,11 @@ gfc_cpp_handle_option (size_t scode, const char *arg, int value ATTRIBUTE_UNUSED
       gfc_cpp_option.deps = 1;
       break;
 
-    case OPT_MMD:
+    case OPT_MMDX:
       gfc_cpp_option.deps_skip_system = 1;
       /* fall through */
 
-    case OPT_MD:
+    case OPT_MDX:
       gfc_cpp_option.deps = 1;
       gfc_cpp_option.deps_filename = arg;
       break;
diff --git a/gcc/fortran/lang.opt b/gcc/fortran/lang.opt
index 2f73316773ff..453a24136241 100644
--- a/gcc/fortran/lang.opt
+++ b/gcc/fortran/lang.opt
@@ -60,7 +60,7 @@ M
 Fortran
 ; Documented in C
 
-MD
+MDX
 Fortran Separate
 ; Documented in C
 
@@ -76,7 +76,7 @@ MM
 Fortran
 ; Documented in C
 
-MMD
+MMDX
 Fortran Separate
 ; Documented in C
 
diff --git a/gcc/gcc.c b/gcc/gcc.c
index 35a1b1ef413e..8aef83b82ef7 100644
--- a/gcc/gcc.c
+++ b/gcc/gcc.c
@@ -829,8 +829,8 @@ static const char *trad_capable_cpp =
    file that happens to exist is up-to-date.  */
 static const char *cpp_unique_options =
 "%{!Q:-quiet} %{nostdinc*} %{C} %{CC} %{v} %{I*&F*} %{P} %I\
- %{MD:-MD %{!o:%b.d}%{o*:%.d%*}}\
- %{MMD:-MMD %{!o:%b.d}%{o*:%.d%*}}\
+ %{MD:-MDX %{!o:%b.d}%{o*:%.d%*}}\
+ %{MMD:-MMDX %{!o:%b.d}%{o*:%.d%*}}\
  %{M} %{MM} %{MF*} %{MG} %{MP} %{MQ*} %{MT*}\
  %{!E:%{!M:%{!MM:%{!MT:%{!MQ:%{MD|MMD:%{o*:-MQ %*}}}}}}}\
  %{remap} %{g3|ggdb3|gstabs3|gcoff3|gxcoff3|gvms3:-dD}\