diff --git a/package/socat/socat.mk b/package/socat/socat.mk
index e20577492d..c1bf4d260f 100644
--- a/package/socat/socat.mk
+++ b/package/socat/socat.mk
@@ -11,6 +11,14 @@ SOCAT_LICENSE = GPL-2.0 with OpenSSL exception
 SOCAT_LICENSE_FILES = README COPYING COPYING.OpenSSL
 SOCAT_CPE_ID_VENDOR = dest-unreach
 
+SOCAT_CONF_ENV = ac_cv_have_c99_snprintf=yes
+
+ifeq ($(BR2_TOOLCHAIN_USES_GLIBC)$(BR2_TOOLCHAIN_USES_UCLIBC),y)
+SOCAT_CONF_ENV += ac_cv_have_z_modifier=yes
+else
+SOCAT_CONF_ENV += ac_cv_have_z_modifier=no
+endif
+
 ifeq ($(BR2_powerpc)$(BR2_powerpc64)$(BR2_powerpc64le),y)
 SOCAT_CONF_ENV += \
 	sc_cv_sys_crdly_shift=12 \