diff --git a/shared/nm-glib-aux/nm-shared-utils.h b/shared/nm-glib-aux/nm-shared-utils.h
index 7efb8aed52..a097a690c8 100644
--- a/shared/nm-glib-aux/nm-shared-utils.h
+++ b/shared/nm-glib-aux/nm-shared-utils.h
@@ -8,6 +8,12 @@
 
 #include <netinet/in.h>
 
+static inline gboolean
+nm_is_ascii (char ch)
+{
+	return ((uint8_t) ch) < 128;
+}
+
 /*****************************************************************************/
 
 pid_t nm_utils_gettid (void);