diff --git a/configure.ac b/configure.ac
index 1085d7cb9c..8544f3c4b8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -408,6 +408,7 @@ elif test "x${ax_cv_c_compiler_vendor}" = "xclang" ; then
 elif test "x${ax_cv_c_compiler_vendor}" = "xgnu" ; then
     APR_ADDTO(SWITCH_AM_CFLAGS, -fPIC)
     APR_ADDTO(SWITCH_AM_CXXFLAGS, -fPIC)
+    AC_SUBST([AM_MOD_AVMD_CXXFLAGS], [-std=gnu99])      # FS-8809, needed for MAP_POPULATE
     if test "$ac_cv_gcc_supports_w_no_unused_result" = yes; then
       APR_ADDTO(SWITCH_AM_CFLAGS, -Werror)
     fi
diff --git a/src/mod/applications/mod_avmd/Makefile.am b/src/mod/applications/mod_avmd/Makefile.am
index 0387fee18f..ce877babf7 100644
--- a/src/mod/applications/mod_avmd/Makefile.am
+++ b/src/mod/applications/mod_avmd/Makefile.am
@@ -3,6 +3,6 @@ MODNAME=mod_avmd
 
 mod_LTLIBRARIES = mod_avmd.la
 mod_avmd_la_SOURCES  = mod_avmd.c amplitude.c buffer.c desa2.c goertzel.c fast_acosf.c
-mod_avmd_la_CFLAGS   = $(AM_CFLAGS)
+mod_avmd_la_CFLAGS   = $(AM_CFLAGS) $(AM_MOD_AVMD_CXXFLAGS)
 mod_avmd_la_LIBADD   = $(switch_builddir)/libfreeswitch.la
 mod_avmd_la_LDFLAGS  = -avoid-version -module -no-undefined -shared