diff --git a/src/ddmd/root/ctfloat.h b/src/ddmd/root/ctfloat.h
index c3597427924e..d3a33c657086 100644
--- a/src/ddmd/root/ctfloat.h
+++ b/src/ddmd/root/ctfloat.h
@@ -38,6 +38,8 @@ struct CTFloat
     static real_t parse(const char *literal, bool *isOutOfRange = NULL);
     static int sprint(char *str, char fmt, real_t x);
 
+    static size_t hash(real_t a);
+
     // Constant real values 0, 1, -1 and 0.5.
     static real_t zero;
     static real_t one;