diff --git a/mozilla/config/rules.mk b/mozilla/config/rules.mk
index 26a75e668d3..d3ba36a42f7 100644
--- a/mozilla/config/rules.mk
+++ b/mozilla/config/rules.mk
@@ -1110,7 +1110,24 @@ ifdef MOZ_POST_DSO_LIB_COMMAND
 endif
 
 ifdef MOZ_AUTO_DEPS
-ifndef COMPILER_DEPEND
+ifdef COMPILER_DEPEND
+ifeq (__SunOS,$(GNU_CC)_$(GNU_CXX)_$(OS_ARCH))
+_MDDEPFILE = $(MDDEPDIR)/$(@F).pp
+
+define MAKE_DEPS_AUTO_CC
+if test -d $(@D); then \
+	echo "Building deps for $< using Sun Studio cc"; \
+	$(CC) $(COMPILE_CFLAGS) -xM  $< >$(_MDDEPFILE) ; \
+fi
+endef
+define MAKE_DEPS_AUTO_CXX
+if test -d $(@D); then \
+	echo "Building deps for $< using Sun Studio CC"; \
+	$(CXX) $(COMPILE_CXXFLAGS) -xM $< >$(_MDDEPFILE) ; \
+fi
+endef
+endif # Sun Studio on Solaris
+else # COMPILER_DEPEND
 #
 # Generate dependencies on the fly
 #
@@ -1137,7 +1154,11 @@ if test -d $(@D); then \
 fi
 endef
 endif # WINNT
-endif # !COMPILER_DEPEND
+
+MAKE_DEPS_AUTO_CC = $(MAKE_DEPS_AUTO)
+MAKE_DEPS_AUTO_CXX = $(MAKE_DEPS_AUTO)
+
+endif # COMPILER_DEPEND
 
 endif # MOZ_AUTO_DEPS
 
@@ -1164,12 +1185,12 @@ host_%.$(OBJ_SUFFIX): %.mm Makefile Makefile.in
 
 %: %.c Makefile Makefile.in
 	$(REPORT_BUILD)
-	@$(MAKE_DEPS_AUTO)
+	@$(MAKE_DEPS_AUTO_CC)
 	$(ELOG) $(CC) $(CFLAGS) $(LDFLAGS) $(OUTOPTION)$@ $(_VPATH_SRCS)
 
 %.$(OBJ_SUFFIX): %.c Makefile Makefile.in
 	$(REPORT_BUILD)
-	@$(MAKE_DEPS_AUTO)
+	@$(MAKE_DEPS_AUTO_CC)
 	$(ELOG) $(CC) $(OUTOPTION)$@ -c $(COMPILE_CFLAGS) $(_VPATH_SRCS)
 
 moc_%.cpp: %.h Makefile Makefile.in
@@ -1188,7 +1209,7 @@ endif
 	$(AS) -o $@ $(ASFLAGS) -c $<
 
 %: %.cpp Makefile Makefile.in
-	@$(MAKE_DEPS_AUTO)
+	@$(MAKE_DEPS_AUTO_CXX)
 	$(CCC) $(OUTOPTION)$@ $(CXXFLAGS) $(_VPATH_SRCS) $(LDFLAGS)
 
 #
@@ -1196,12 +1217,12 @@ endif
 #
 %.$(OBJ_SUFFIX): %.cc Makefile Makefile.in
 	$(REPORT_BUILD)
-	@$(MAKE_DEPS_AUTO)
+	@$(MAKE_DEPS_AUTO_CXX)
 	$(ELOG) $(CCC) $(OUTOPTION)$@ -c $(COMPILE_CXXFLAGS) $(_VPATH_SRCS)
 
 %.$(OBJ_SUFFIX): %.cpp Makefile Makefile.in
 	$(REPORT_BUILD)
-	@$(MAKE_DEPS_AUTO)
+	@$(MAKE_DEPS_AUTO_CXX)
 ifdef STRICT_CPLUSPLUS_SUFFIX
 	echo "#line 1 \"$*.cpp\"" | cat - $*.cpp > t_$*.cc
 	$(ELOG) $(CCC) -o $@ -c $(COMPILE_CXXFLAGS) t_$*.cc
@@ -1212,12 +1233,12 @@ endif #STRICT_CPLUSPLUS_SUFFIX
 
 $(OBJ_PREFIX)%.$(OBJ_SUFFIX): %.mm Makefile Makefile.in
 	$(REPORT_BUILD)
-	@$(MAKE_DEPS_AUTO)
+	@$(MAKE_DEPS_AUTO_CXX)
 	$(ELOG) $(CCC) -o $@ -c $(COMPILE_CXXFLAGS) $(_VPATH_SRCS)
 
 $(OBJ_PREFIX)%.$(OBJ_SUFFIX): %.m Makefile Makefile.in
 	$(REPORT_BUILD)
-	@$(MAKE_DEPS_AUTO)
+	@$(MAKE_DEPS_AUTO_CC)
 	$(ELOG) $(CC) -o $@ -c $(COMPILE_CFLAGS) $(_VPATH_SRCS)
 
 %.s: %.cpp
diff --git a/mozilla/configure.in b/mozilla/configure.in
index a7a247c8a04..3d5c54edce6 100644
--- a/mozilla/configure.in
+++ b/mozilla/configure.in
@@ -6669,6 +6669,10 @@ MOZ_ARG_DISABLE_BOOL(md,
   [dnl Default is to turn on -MD if using GNU-compatible compilers
    if test "$GNU_CC" -a "$GNU_CXX" -a "$OS_ARCH" != "WINNT" -a "$OS_ARCH" != "WINCE"; then
      _cpp_md_flag=1
+   fi
+  dnl Default is to use -xM if using Sun Studio on Solaris
+   if test -z "$GNU_CC" && test -z "$GNU_CXX" && test "$OS_ARCH" = "SunOS"; then
+     _cpp_md_flag=1
    fi])
 if test "$_cpp_md_flag"; then
   COMPILER_DEPEND=1
@@ -6677,6 +6681,10 @@ if test "$_cpp_md_flag"; then
   else
     _DEPEND_CFLAGS='$(filter-out %/.pp,-Wp,-MD,$(MDDEPDIR)/$(*F).pp)'
   fi
+  dnl Sun Studio on Solaris use -xM instead of -MD, see config/rules.mk
+  if test -z "$GNU_CC" && test -z "$GNU_CXX" && test "$OS_ARCH" = "SunOS"; then
+    _DEPEND_CFLAGS=
+  fi
 else
   COMPILER_DEPEND=
   _USE_CPP_INCLUDE_FLAG=
diff --git a/mozilla/js/src/Makefile.in b/mozilla/js/src/Makefile.in
index 678e1010377..8566d83cd41 100644
--- a/mozilla/js/src/Makefile.in
+++ b/mozilla/js/src/Makefile.in
@@ -299,7 +299,7 @@ ifndef GNU_CC
 _COMPILE_CFLAGS  = $(patsubst -O%,-O1,$(COMPILE_CFLAGS))
 jsapi.o jsxdrapi.o jsarena.o jsarray.o jsatom.o jsemit.o jsfun.o jsinterp.o jsregexp.o jsparse.o jsopcode.o jsscript.o: %.o: %.c Makefile.in
 	$(REPORT_BUILD)
-	@$(MAKE_DEPS_AUTO)
+	@$(MAKE_DEPS_AUTO_CC)
 	$(CC) -o $@ -c $(_COMPILE_CFLAGS) $<
 endif
 endif
@@ -309,11 +309,11 @@ endif
 ifeq ($(OS_ARCH),AIX)
 jsatom.o: jsatom.c Makefile.in
 	$(REPORT_BUILD)
-	@$(MAKE_DEPS_AUTO)
+	@$(MAKE_DEPS_AUTO_CC)
 	$(CC) -o $@ -c $(filter-out $(MOZ_OPTIMIZE_FLAGS), $(COMPILE_CFLAGS)) $<
 jsdtoa.o: jsdtoa.c Makefile.in
 	$(REPORT_BUILD)
-	@$(MAKE_DEPS_AUTO)
+	@$(MAKE_DEPS_AUTO_CC)
 	$(CC) -o $@ -c $(filter-out $(MOZ_OPTIMIZE_FLAGS), $(COMPILE_CFLAGS)) $<
 endif
 
diff --git a/mozilla/modules/libpref/src/Makefile.in b/mozilla/modules/libpref/src/Makefile.in
index 15381a8dc86..cd8a794793d 100644
--- a/mozilla/modules/libpref/src/Makefile.in
+++ b/mozilla/modules/libpref/src/Makefile.in
@@ -106,6 +106,6 @@ GARBAGE		+= $(addprefix $(DIST)/bin/defaults/pref/, \
 ifeq ($(OS_ARCH), OS2)
 nsPrefService.$(OBJ_SUFFIX): nsPrefService.cpp
 	$(REPORT_BUILD)
-	@$(MAKE_DEPS_AUTO)
+	@$(MAKE_DEPS_AUTO_CXX)
 	$(ELOG) $(CCC) $(OUTOPTION)$@ -c $(COMPILE_CXXFLAGS:-O2=-O1) $(_VPATH_SRCS)
 endif