diff --git a/Defs/ResearchProjectDefs/ResearchProjects.xml b/Defs/ResearchProjectDefs/ResearchProjects.xml
index e2982e6933..04d85c20be 100644
--- a/Defs/ResearchProjectDefs/ResearchProjects.xml
+++ b/Defs/ResearchProjectDefs/ResearchProjects.xml
@@ -39,7 +39,7 @@
 		<generalRules>
 			<rulesStrings>
 				<li>subject->grenade launchers</li>
-				<li>subject->rocket launchers launchers</li>
+				<li>subject->rocket launchers</li>
 
 				<li>subject_story->developed weapons to defeat heavily armored foes</li>
 				<li>subject_story->toiled in an urbworld munitions factory</li>