diff --git a/io/dcache/src/TDCacheFile.cxx b/io/dcache/src/TDCacheFile.cxx
index 6edade9942cec..1515d150ddf02 100644
--- a/io/dcache/src/TDCacheFile.cxx
+++ b/io/dcache/src/TDCacheFile.cxx
@@ -140,7 +140,7 @@ TDCacheFile::TDCacheFile(const char *path, Option_t *option,
 
    if (create || update) {
 #ifndef WIN32
-      fD = SysOpen(fname, O_RDWR | O_CREAT, 0644);
+      fD = SysOpen(fname, O_RDWR | O_CREAT, 0666);
 #else
       fD = SysOpen(fname, O_RDWR | O_CREAT | O_BINARY, S_IREAD | S_IWRITE);
 #endif
@@ -151,7 +151,7 @@ TDCacheFile::TDCacheFile(const char *path, Option_t *option,
       fWritable = kTRUE;
    } else {
 #ifndef WIN32
-      fD = SysOpen(fname, O_RDONLY, 0644);
+      fD = SysOpen(fname, O_RDONLY, 0666);
 #else
       fD = SysOpen(fname, O_RDONLY | O_BINARY, S_IREAD | S_IWRITE);
 #endif
diff --git a/io/io/src/TFile.cxx b/io/io/src/TFile.cxx
index 35b4acddc184a..c8d7030215f0c 100644
--- a/io/io/src/TFile.cxx
+++ b/io/io/src/TFile.cxx
@@ -533,7 +533,7 @@ TFile::TFile(const char *fname1, Option_t *option, const char *ftitle, Int_t com
    // Connect to file system stream
    if (create || update) {
 #ifndef WIN32
-      fD = TFile::SysOpen(fname.Data(), O_RDWR | O_CREAT, 0644);
+      fD = TFile::SysOpen(fname.Data(), O_RDWR | O_CREAT, 0666);
 #else
       fD = TFile::SysOpen(fname.Data(), O_RDWR | O_CREAT | O_BINARY, S_IREAD | S_IWRITE);
 #endif
@@ -545,7 +545,7 @@ TFile::TFile(const char *fname1, Option_t *option, const char *ftitle, Int_t com
       fWritable = kTRUE;
    } else {
 #ifndef WIN32
-      fD = TFile::SysOpen(fname.Data(), O_RDONLY, 0644);
+      fD = TFile::SysOpen(fname.Data(), O_RDONLY, 0666);
 #else
       fD = TFile::SysOpen(fname.Data(), O_RDONLY | O_BINARY, S_IREAD | S_IWRITE);
 #endif
@@ -2236,7 +2236,7 @@ Int_t TFile::ReOpen(Option_t *mode)
       // open in READ mode
       fOption = opt;    // set fOption before SysOpen() for TNetFile
 #ifndef WIN32
-      fD = SysOpen(fRealName, O_RDONLY, 0644);
+      fD = SysOpen(fRealName, O_RDONLY, 0666);
 #else
       fD = SysOpen(fRealName, O_RDONLY | O_BINARY, S_IREAD | S_IWRITE);
 #endif
@@ -2258,7 +2258,7 @@ Int_t TFile::ReOpen(Option_t *mode)
       // open in UPDATE mode
       fOption = opt;    // set fOption before SysOpen() for TNetFile
 #ifndef WIN32
-      fD = SysOpen(fRealName, O_RDWR | O_CREAT, 0644);
+      fD = SysOpen(fRealName, O_RDWR | O_CREAT, 0666);
 #else
       fD = SysOpen(fRealName, O_RDWR | O_CREAT | O_BINARY, S_IREAD | S_IWRITE);
 #endif
diff --git a/io/io/src/TMapFile.cxx b/io/io/src/TMapFile.cxx
index 436cdd805e960..8bf9fb7f29153 100644
--- a/io/io/src/TMapFile.cxx
+++ b/io/io/src/TMapFile.cxx
@@ -333,7 +333,7 @@ TMapFile::TMapFile(const char *name, const char *title, Option_t *option,
    // Open file to which memory will be mapped
    if (create || update) {
 #ifndef WIN32
-      fFd = open(fname, O_RDWR | O_CREAT, 0644);
+      fFd = open(fname, O_RDWR | O_CREAT, 0666);
 #else
       fFd = (Longptr_t) CreateFile(fname,                    // pointer to name of the file
                      GENERIC_WRITE | GENERIC_READ,       // access (read-write) mode
diff --git a/io/io/src/TMemFile.cxx b/io/io/src/TMemFile.cxx
index cf134cbb3458b..a738d0ca9732b 100644
--- a/io/io/src/TMemFile.cxx
+++ b/io/io/src/TMemFile.cxx
@@ -179,7 +179,7 @@ TMemFile::TMemFile(const char *path, char *buffer, Long64_t size, Option_t *opti
       Int_t mode = O_RDWR | O_CREAT;
       if (optmode == EMode::kRecreate) mode |= O_TRUNC;
 
-      fD = TMemFile::SysOpen(path, mode, 0644);
+      fD = TMemFile::SysOpen(path, mode, 0666);
       if (fD == -1) {
          SysError("TMemFile", "file %s can not be opened", path);
          goto zombie;
@@ -187,7 +187,7 @@ TMemFile::TMemFile(const char *path, char *buffer, Long64_t size, Option_t *opti
       fWritable = kTRUE;
 
    } else {
-      fD = TMemFile::SysOpen(path, O_RDONLY, 0644);
+      fD = TMemFile::SysOpen(path, O_RDONLY, 0666);
       if (fD == -1) {
          SysError("TMemFile", "file %s can not be opened for reading", path);
          goto zombie;
diff --git a/net/net/src/TApplicationServer.cxx b/net/net/src/TApplicationServer.cxx
index 4eaa93dd68d10..6fea7483a9d41 100644
--- a/net/net/src/TApplicationServer.cxx
+++ b/net/net/src/TApplicationServer.cxx
@@ -788,7 +788,7 @@ Int_t TApplicationServer::ReceiveFile(const char *file, Bool_t bin, Long64_t siz
 
    close(fd);
 
-   chmod(file, 0644);
+   chmod(file, 0666);
 
    return 0;
 }
diff --git a/net/net/src/TFTP.cxx b/net/net/src/TFTP.cxx
index af77ee52384e5..e87a623f6bf12 100644
--- a/net/net/src/TFTP.cxx
+++ b/net/net/src/TFTP.cxx
@@ -593,7 +593,7 @@ Long64_t TFTP::GetFile(const char *file, const char *localName)
    delete [] buf; delete [] buf2;
 
 #ifndef R__WIN32
-   fchmod(fd, 0644);
+   fchmod(fd, 0666);
 #endif
 
    close(fd);