diff --git a/include/types/backend.h b/include/types/backend.h
index e392a7b..2b35860 100644
--- a/include/types/backend.h
+++ b/include/types/backend.h
@@ -44,7 +44,16 @@
 #define BE_LB_ALGO_PH	(BE_LB_PROP_L7  | 0x04) /* balance on URL parameter hash */
 
 /* various constants */
-#define BE_WEIGHT_SCALE 256             /* scale between user weight and effective weight */
+
+/* The scale factor between user weight an effective weight allows smooth
+ * weight modulation even with small weights (eg: 1). It should not be too high
+ * though because it limits the number of servers in FWRR mode in order to
+ * prevent any integer overflow. The max number of servers per backend is
+ * limited to about 2^32/255^2/scale ~= 66051/scale. A scale of 16 looks like
+ * a good value, as it allows more than 4000 servers per backend while leaving
+ * modulation steps of about 6% for servers with the lowest weight (1).
+ */
+#define BE_WEIGHT_SCALE 16
 
 #endif /* _TYPES_BACKEND_H */