diff --git a/libstdc++-v3/src/Makefile.am b/libstdc++-v3/src/Makefile.am
index 16f4cc6eff4..f27d3f8c87e 100644
--- a/libstdc++-v3/src/Makefile.am
+++ b/libstdc++-v3/src/Makefile.am
@@ -369,7 +369,7 @@ endif
 # Build a debug variant.
 # Take care to fix all possibly-relative paths.
 debugdir = ${glibcxx_builddir}/src/debug
-stamp-debug:
+stamp-debug: Makefile $(foreach dir,$(SUBDIRS),$(dir)/Makefile)
 	if test ! -d ${debugdir} || test ! -f ${debugdir}/Makefile ; then \
 	  mkdir -p ${debugdir}; \
 	  for d in $(SUBDIRS); do mkdir -p  ${debugdir}/$$d; done; \
diff --git a/libstdc++-v3/src/Makefile.in b/libstdc++-v3/src/Makefile.in
index 4df5c829a7f..05b25ed5e9d 100644
--- a/libstdc++-v3/src/Makefile.in
+++ b/libstdc++-v3/src/Makefile.in
@@ -1090,7 +1090,7 @@ libstdc++convenience.la: $(toolexeclib_LTLIBRARIES)
 	  cp .libs/libstdc++convenience.a .libs/libstdc++.a; \
 	fi; \
 	echo `date` > stamp-libstdc++convenience;
-stamp-debug:
+stamp-debug: Makefile $(foreach dir,$(SUBDIRS),$(dir)/Makefile)
 	if test ! -d ${debugdir} || test ! -f ${debugdir}/Makefile ; then \
 	  mkdir -p ${debugdir}; \
 	  for d in $(SUBDIRS); do mkdir -p  ${debugdir}/$$d; done; \