diff --git a/CHANGELOG b/CHANGELOG
index 969bcfc06c..222ed76a04 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -97,6 +97,10 @@ Next:
   - Added breakpoint type "Freeze memory" (Enmet)
   - Implemented seeking in MSCDEX
     (Imported from dosbox-staging/dosbox-staging#3516 authored by weirddan455)
+  - Fixed built-in COPY command failed to obtain free space when reported DOS 
+    version is set to 7.1 (maron2000)
+  - Fixed some file extensions in tbe filter list were ignored in the file open
+    dialogs (maron2000)
 
 2024.03.01
   - If an empty CD-ROM drive is attached to IDE emulation, return "Medium Not
diff --git a/src/dos/dos_programs.cpp b/src/dos/dos_programs.cpp
index 483e172c98..50b2370534 100644
--- a/src/dos/dos_programs.cpp
+++ b/src/dos/dos_programs.cpp
@@ -551,7 +551,7 @@ void MenuBrowseCDImage(char drive, int num) {
     std::string files="", fname="";
     const char *lFilterPatterns[] = {"*.iso","*.cue","*.bin","*.chd","*.mdf","*.gog","*.ins","*.ISO","*.CUE","*.BIN","*.CHD","*.MDF","*.GOG","*.INS"};
     const char *lFilterDescription = "CD image files (*.iso, *.cue, *.bin, *.chd, *.mdf, *.gog, *.ins)";
-    lTheOpenFileName = tinyfd_openFileDialog("Select a CD image file","",14,lFilterPatterns,lFilterDescription,0);
+    lTheOpenFileName = tinyfd_openFileDialog("Select a CD image file","", sizeof(lFilterPatterns) / sizeof(lFilterPatterns[0]),lFilterPatterns,lFilterDescription,0);
 
     if (lTheOpenFileName) {
         isoDrive *cdrom = dynamic_cast<isoDrive*>(Drives[drive-'A']);
@@ -597,7 +597,7 @@ void MenuBrowseFDImage(char drive, int num, int type) {
     std::string files="", fname="";
     const char *lFilterPatterns[] = {"*.ima","*.img","*.xdf","*.fdi","*.hdm","*.nfd","*.d88","*.IMA","*.IMG","*.XDF","*.FDI","*.HDM","*.NFD","*.D88"};
     const char *lFilterDescription = "Floppy image files (*.ima, *.img, *.xdf, *.fdi, *.hdm, *.nfd, *.d88)";
-    lTheOpenFileName = tinyfd_openFileDialog("Select a floppy image file","",4,lFilterPatterns,lFilterDescription,0);
+    lTheOpenFileName = tinyfd_openFileDialog("Select a floppy image file","",sizeof(lFilterPatterns)/sizeof(lFilterPatterns[0]), lFilterPatterns, lFilterDescription, 0);
 
     if (lTheOpenFileName) {
         //uint8_t mediaid = 0xF0; UNUSED
@@ -654,12 +654,12 @@ void MenuBrowseImageFile(char drive, bool arc, bool boot, bool multiple) {
     if (arc) {
         const char *lFilterPatterns[] = {"*.zip","*.7z","*.ZIP","*.7Z"};
         const char *lFilterDescription = "Archive files (*.zip, *.7z)";
-        lTheOpenFileName = tinyfd_openFileDialog(("Select an archive file for Drive "+str+":").c_str(),"",4,lFilterPatterns,lFilterDescription,0);
+        lTheOpenFileName = tinyfd_openFileDialog(("Select an archive file for Drive "+str+":").c_str(),"", sizeof(lFilterPatterns) / sizeof(lFilterPatterns[0]),lFilterPatterns,lFilterDescription,0);
         if (lTheOpenFileName) fname = GetNewStr(lTheOpenFileName);
     } else {
         const char *lFilterPatterns[] = {"*.ima","*.img","*.vhd","*.fdi","*.hdi","*.nfd","*.nhd","*.d88","*.hdm","*.xdf","*.iso","*.cue","*.bin","*.chd","*.mdf","*.gog","*.ins","*.ccd","*.IMA","*.IMG","*.VHD","*.FDI","*.HDI","*.NFD","*.NHD","*.D88","*.HDM","*.XDF","*.ISO","*.CUE","*.BIN","*.CHD","*.MDF","*.GOG","*.INS", "*.CCD"};
         const char *lFilterDescription = "Disk/CD image files";
-        lTheOpenFileName = tinyfd_openFileDialog(((multiple?"Select image file(s) for Drive ":"Select an image file for Drive ")+str+":").c_str(),"",22,lFilterPatterns,lFilterDescription,multiple?1:0);
+        lTheOpenFileName = tinyfd_openFileDialog(((multiple?"Select image file(s) for Drive ":"Select an image file for Drive ")+str+":").c_str(),"", sizeof(lFilterPatterns) / sizeof(lFilterPatterns[0]),lFilterPatterns,lFilterDescription,multiple?1:0);
         if (lTheOpenFileName) fname = GetNewStr(lTheOpenFileName);
         if (multiple&&fname.size()) {
             files += "\"";
@@ -668,7 +668,7 @@ void MenuBrowseImageFile(char drive, bool arc, bool boot, bool multiple) {
             files += "\" ";
         }
         while (multiple&&lTheOpenFileName&&systemmessagebox("Mount image files","Do you want to mount more image file(s)?","yesno", "question", 1)) {
-            lTheOpenFileName = tinyfd_openFileDialog(("Select image file(s) for Drive "+str+":").c_str(),"",20,lFilterPatterns,lFilterDescription,multiple?1:0);
+            lTheOpenFileName = tinyfd_openFileDialog(("Select image file(s) for Drive "+str+":").c_str(),"", sizeof(lFilterPatterns) / sizeof(lFilterPatterns[0]),lFilterPatterns,lFilterDescription,multiple?1:0);
             if (lTheOpenFileName) {
                 fname = GetNewStr(lTheOpenFileName);
                 files += "\"";