diff --git a/ac/curl.m4 b/ac/curl.m4
index 017f64f16..dda6d0b3c 100644
--- a/ac/curl.m4
+++ b/ac/curl.m4
@@ -6,6 +6,7 @@ PKG_CHECK_MODULES([CURL], [libcurl], [curl_found=yes])
 
 if test "$curl_found" = "yes"; then
   opt_features_yes="$opt_features_yes\n   * online update checks (via libcurl)"
+  AC_DEFINE(HAVE_CURL_EASY_H, 1, [define if libcurl is found via pkg-config])
 else
   opt_features_no="$opt_features_no\n   * online update checks (via libcurl)"
   CURL_CFLAGS=""