diff --git a/include/FLAC++/export.h b/include/FLAC++/export.h
index ab17410c..e3bc51fc 100644
--- a/include/FLAC++/export.h
+++ b/include/FLAC++/export.h
@@ -69,7 +69,7 @@
 #endif
 
 /* These #defines will mirror the libtool-based library version number, see
- * http://www.gnu.org/software/libtool/manual.html#Libtool-versioning
+ * http://www.gnu.org/software/libtool/manual/libtool.html#Libtool-versioning
  */
 #define FLACPP_API_VERSION_CURRENT 8
 #define FLACPP_API_VERSION_REVISION 0
diff --git a/include/FLAC/all.h b/include/FLAC/all.h
index a39ad6f3..1aa3f7bd 100644
--- a/include/FLAC/all.h
+++ b/include/FLAC/all.h
@@ -161,7 +161,7 @@
  * in FLAC 1.1.3 is a set of \c #defines in \c export.h of each
  * library's includes (e.g. \c include/FLAC/export.h).  The
  * \c #defines mirror the libraries'
- * <A HREF="http://www.gnu.org/software/libtool/manual.html#Libtool-versioning">libtool version numbers</A>,
+ * <A HREF="http://www.gnu.org/software/libtool/manual/libtool.html#Libtool-versioning">libtool version numbers</A>,
  * e.g. in libFLAC there are \c FLAC_API_VERSION_CURRENT,
  * \c FLAC_API_VERSION_REVISION, and \c FLAC_API_VERSION_AGE.
  * These can be used to support multiple versions of an API during the
diff --git a/include/FLAC/export.h b/include/FLAC/export.h
index 35a540cb..d239b9b7 100644
--- a/include/FLAC/export.h
+++ b/include/FLAC/export.h
@@ -69,7 +69,7 @@
 #endif
 
 /** These #defines will mirror the libtool-based library version number, see
- * http://www.gnu.org/software/libtool/manual.html#Libtool-versioning
+ * http://www.gnu.org/software/libtool/manual/libtool.html#Libtool-versioning
  */
 #define FLAC_API_VERSION_CURRENT 10
 #define FLAC_API_VERSION_REVISION 0 /**< see above */
diff --git a/src/libFLAC++/Makefile.am b/src/libFLAC++/Makefile.am
index 444b160f..03155f63 100644
--- a/src/libFLAC++/Makefile.am
+++ b/src/libFLAC++/Makefile.am
@@ -45,7 +45,7 @@ EXTRA_DIST = \
 	libFLAC++_static.vcproj \
 	libFLAC++.m4
 
-# see 'http://www.gnu.org/software/libtool/manual.html#Libtool-versioning' for numbering convention
+# see 'http://www.gnu.org/software/libtool/manual/libtool.html#Libtool-versioning' for numbering convention
 libFLAC___la_LDFLAGS = -version-info 8:0:3 @LT_NO_UNDEFINED@
 libFLAC___la_LIBADD = ../libFLAC/libFLAC.la
 
diff --git a/src/libFLAC/Makefile.am b/src/libFLAC/Makefile.am
index 134168eb..b20e21ae 100644
--- a/src/libFLAC/Makefile.am
+++ b/src/libFLAC/Makefile.am
@@ -104,7 +104,7 @@ extra_ogg_sources = \
 	ogg_helper.c \
 	ogg_mapping.c
 endif
-# see 'http://www.gnu.org/software/libtool/manual.html#Libtool-versioning' for numbering convention
+# see 'http://www.gnu.org/software/libtool/manual/libtool.html#Libtool-versioning' for numbering convention
 libFLAC_la_LDFLAGS = -version-info 10:0:2 $(LOCAL_EXTRA_LDFLAGS) @LT_NO_UNDEFINED@
 libFLAC_la_SOURCES = \
 	bitmath.c \