diff --git a/src/scriptengine.cpp b/src/scriptengine.cpp
index 61be4a9..5c933a6 100644
--- a/src/scriptengine.cpp
+++ b/src/scriptengine.cpp
@@ -608,7 +608,7 @@ bool File::modifyFITSRecords(const FITSRecordModify *modify)
     _fitsKeywordsLoaded = false;
     _fitsKeywords.clear();
 
-    if(QRegularExpression("(fits?|fz|fts)", QRegularExpression::CaseInsensitiveOption).match(suffix()).hasMatch())
+    if(isFITS(suffix()))
     {
         fitsfile *file;
         int status = 0;
@@ -731,7 +731,7 @@ bool File::modifyFITSRecords(const FITSRecordModify *modify)
 
         return status == 0;
     }
-    else if(suffix().toLower() == "xisf")
+    else if(isXISF(suffix()))
     {
         try
         {