diff --git a/configure b/configure
index 67673a2f..952cd9a4 100755
--- a/configure
+++ b/configure
@@ -2278,11 +2278,10 @@ See 'config.log' for more details" "$LINENO" 5; }
 fi
 
 ################# Begin configuration to use system libgit2 ##################
-# The function 'git_buf_free' is deprecated in libgit2
-# v0.28.0. Use 'git_buf_dispose', if available, instead.
+# Check for new sys subfolfder in libgit2.
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether libgit2 includes new sys subfolder" >&5
 printf %s "checking whether libgit2 includes new sys subfolder... " >&6; }
-have_buf_dispose=no
+have_sys_subfolder=no
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 #include <git2/sys/errors.h>
@@ -2294,7 +2293,7 @@ git_error_set_str(0, NULL);
   return 0;
 }
 _ACEOF
-PKG_CFLAGS="${PKG_CFLAGS} -Werror" "$RBIN" CMD SHLIB conftest.c \
+PKG_CFLAGS="${PKG_CFLAGS}" "$RBIN" CMD SHLIB conftest.c \
 1>&5 2>&5 && have_sys_subfolder=yes
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: ${have_sys_subfolder}" >&5
 printf "%s\n" "${have_sys_subfolder}" >&6; }
diff --git a/configure.ac b/configure.ac
index f3174dd2..53f93d0c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -136,14 +136,13 @@ if test "x${libgit2_ver_ok}" = xno; then
 fi
 
 ################# Begin configuration to use system libgit2 ##################
-# The function 'git_buf_free' is deprecated in libgit2
-# v0.28.0. Use 'git_buf_dispose', if available, instead.
+# Check for new sys subfolfder in libgit2.
 AC_MSG_CHECKING([whether libgit2 includes new sys subfolder])
-have_buf_dispose=no
+have_sys_subfolder=no
 AC_LANG_CONFTEST([AC_LANG_PROGRAM(
 [[#include <git2/sys/errors.h>]],
 [[git_error_set_str(0, NULL);]])])
-PKG_CFLAGS="${PKG_CFLAGS} -Werror" "$RBIN" CMD SHLIB conftest.c \
+PKG_CFLAGS="${PKG_CFLAGS}" "$RBIN" CMD SHLIB conftest.c \
 1>&AS_MESSAGE_LOG_FD 2>&AS_MESSAGE_LOG_FD && have_sys_subfolder=yes
 AC_MSG_RESULT([${have_sys_subfolder}])
 if test "x${have_sys_subfolder}" = xyes; then