diff --git a/CHANGELOG.md b/CHANGELOG.md
index d7ce62540..213ba55d3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -115,6 +115,7 @@
     Bug #5092: NPCs with enchanted weapons play sound when out of charges
     Bug #5093: Hand to hand sound plays on knocked out enemies
     Bug #5099: Non-swimming enemies will enter water if player is water walking
+    Bug #5110: ModRegion with a redundant numerical argument breaks script execution
     Feature #1774: Handle AvoidNode
     Feature #2229: Improve pathfinding AI
     Feature #3025: Analogue gamepad movement controls
diff --git a/components/compiler/extensions0.cpp b/components/compiler/extensions0.cpp
index 5b60f9d6d..7ccfb9285 100644
--- a/components/compiler/extensions0.cpp
+++ b/components/compiler/extensions0.cpp
@@ -340,7 +340,7 @@ namespace Compiler
             extensions.registerFunction ("getmasserphase", 'l', "", opcodeGetMasserPhase);
             extensions.registerFunction ("getsecundaphase", 'l', "", opcodeGetSecundaPhase);
             extensions.registerFunction ("getcurrentweather", 'l', "", opcodeGetCurrentWeather);
-            extensions.registerInstruction ("modregion", "S/llllllllll", opcodeModRegion);
+            extensions.registerInstruction ("modregion", "S/llllllllllX", opcodeModRegion);
         }
     }