diff --git a/firmware/common/strcat.c b/firmware/common/strcat.c
new file mode 100644
index 0000000000..e3366d7405
--- /dev/null
+++ b/firmware/common/strcat.c
@@ -0,0 +1,12 @@
+char *strcat(char *s1,
+             const char *s2)
+{
+  char *s = s1;
+
+  while (*s1)
+    s1++;
+
+  while ((*s1++ = *s2++))
+    ;
+  return s;
+}