diff --git a/src/geo.c b/src/geo.c
index 8f6e3f64596cd42dc27c8fb34ead72c8f6e6e94c..2d351d8e0f8780ed6c171bac8ac4d2b52b0edf1e 100644
--- a/src/geo.c
+++ b/src/geo.c
@@ -157,7 +157,10 @@ double extractDistanceOrReply(client *c, robj **argv,
     }
 
     double to_meters = extractUnitOrReply(c,argv[1]);
-    if (to_meters < 0) return -1;
+    if (to_meters < 0) {
+        addReplyError(c,"radius cannot be negative");
+        return -1;
+    }
 
     if (conversion) *conversion = to_meters;
     return distance * to_meters;