diff --git a/info/BTU.t b/info/BTU.t
index 309a762e..99c16823 100644
--- a/info/BTU.t
+++ b/info/BTU.t
@@ -22,7 +22,7 @@ If the game is a blitz, then as soon as your BTUs go below zero, then
 they are automatically set back to the maximum.
 
 (1) Count the number of civs generating BTUs.
-  civs = maximum(999, number of civs in your capital sector)
+  civs = maximum(1000, number of civs in your capital sector)
   Note that if you don't have a capital, then you will get _no_ BTUs.
 
 (2) Find out how many civs are required to make one BTU in one time unit.
diff --git a/src/lib/common/btu.c b/src/lib/common/btu.c
index 25afbe17..8edef74f 100644
--- a/src/lib/common/btu.c
+++ b/src/lib/common/btu.c
@@ -64,8 +64,8 @@ accrued_btus(struct sctstr *cap, int etu)
 	eff = 0.5;
 
     civ = cap->sct_item[I_CIVIL];
-    if (civ > 999)
-	civ = 999;
+    if (civ > 1000)
+	civ = 1000;
 
     return roundavg(etu * civ * eff * btu_build_rate);
 }