diff --git a/Modules/Editors/ProjectCenter/SyntaxDefinition.m b/Modules/Editors/ProjectCenter/SyntaxDefinition.m
index dbfef36..1fc384e 100644
--- a/Modules/Editors/ProjectCenter/SyntaxDefinition.m
+++ b/Modules/Editors/ProjectCenter/SyntaxDefinition.m
@@ -30,6 +30,7 @@
 #import <Foundation/NSScanner.h>
 
 #import <AppKit/NSColor.h>
+#import <AppKit/NSTextStorage.h>
 
 NSDictionary * ParseSyntaxGraphics(NSDictionary * specification)
 {