diff --git a/ApplicationLibCode/ReservoirDataModel/SimulationFile/RigSimulationInputTool.cpp b/ApplicationLibCode/ReservoirDataModel/SimulationFile/RigSimulationInputTool.cpp
index 90986935ca..51ea08a205 100644
--- a/ApplicationLibCode/ReservoirDataModel/SimulationFile/RigSimulationInputTool.cpp
+++ b/ApplicationLibCode/ReservoirDataModel/SimulationFile/RigSimulationInputTool.cpp
@@ -366,6 +366,7 @@ std::set<std::string> RigSimulationInputTool::cropDataKeywordsInDeckFile( RimEcl
 
         const auto& kw = optKw.value();
         if ( !kw.isDataKeyword() ) continue;
+        if ( name == "ACTNUM" ) continue;
         if ( kw.size() != 1 ) continue;
 
         const auto& record = kw.getRecord( 0 );