diff --git a/winpr/libwinpr/utils/json/json.c b/winpr/libwinpr/utils/json/json.c
index 73c064531..cffa62fb6 100644
--- a/winpr/libwinpr/utils/json/json.c
+++ b/winpr/libwinpr/utils/json/json.c
@@ -18,6 +18,7 @@
  * limitations under the License.
  */
 #include <math.h>
+#include <errno.h>
 
 #include <winpr/json.h>
 #include <winpr/assert.h>