diff --git a/buildflags.md b/buildflags.md
index 01ba183..177bd59 100644
--- a/buildflags.md
+++ b/buildflags.md
@@ -15,9 +15,9 @@ This will invoke the `./configure` with arguments (such as
 `--prefix=/usr`) to adjust the paths to the packaging defaults.
 
 As a side effect, this will set the environment variables `CFLAGS`,
-`CXXFLAGS`, `FFLAGS`, `FCFLAGS`, and `LDFLAGS`, so they can be used by
-makefiles and other build tools.  (However, existing values for this
-variables are not overwritten.)
+`CXXFLAGS`, `FFLAGS`, `FCFLAGS`, `LDFLAGS` and `LT_SYS_LIBRARY_PATH`,
+so they can be used by makefiles and other build tools.  (However,
+existing values for these variables are not overwritten.)
 
 If your package does not use autoconf, you can still set the same
 environment variables using
@@ -43,6 +43,9 @@ Individual build flags are also available through RPM macros:
   driver.  At the start of the `%build` section, the environment
   variable `RPM_LD_FLAGS` is set to this value.
 
+The variable `LT_SYS_LIBRARY_PATH` is defined here to prevent the `libtool`
+script (v2.4.6+) from hardcoding %_libdir into the binaries' RPATH.
+
 These RPM macros do not alter shell environment variables.
 
 For some other build tools separate mechanisms exist:
diff --git a/macros b/macros
index c1965e9..cd06548 100644
--- a/macros
+++ b/macros
@@ -52,12 +52,14 @@
 # variables CFLAGS, CXXFLAGS, FFLAGS, FCFLAGS, LDFLAGS if they have
 # not been set already.  RPM_OPT_FLAGS and RPM_LD_FLAGS have already
 # been set implicitly at the start of the %%build section.
+# LT_SYS_LIBRARY_PATH is used by libtool script.
 %set_build_flags \
   CFLAGS="${CFLAGS:-%{build_cflags}}" ; export CFLAGS ; \
   CXXFLAGS="${CXXFLAGS:-%{build_cxxflags}}" ; export CXXFLAGS ; \
   FFLAGS="${FFLAGS:-%{build_fflags}}" ; export FFLAGS ; \
   FCFLAGS="${FCFLAGS:-%{build_fflags}}" ; export FCFLAGS ; \
-  LDFLAGS="${LDFLAGS:-%{build_ldflags}}" ; export LDFLAGS
+  LDFLAGS="${LDFLAGS:-%{build_ldflags}}" ; export LDFLAGS ; \
+  LT_SYS_LIBRARY_PATH="${LT_SYS_LIBRARY_PATH:-%_libdir:}" ; export LT_SYS_LIBRARY_PATH
 
 # Internal-only.  Do not use.  Expand a variable and strip the flags
 # not suitable to extension builders.