diff --git a/lib/profile/InstrProfilingFile.c b/lib/profile/InstrProfilingFile.c
index 553baad..b36b550 100644
--- a/lib/profile/InstrProfilingFile.c
+++ b/lib/profile/InstrProfilingFile.c
@@ -574,8 +574,10 @@
 
   EnvFilenamePat = getFilenamePatFromEnv();
   if (EnvFilenamePat) {
-    SelectedPat = EnvFilenamePat;
-    PNS = PNS_environment;
+    /* Pass CopyFilenamePat = 1, to ensure that the filename would be valid 
+       at the  moment when __llvm_profile_write_file() gets executed. */
+    parseAndSetFilename(EnvFilenamePat, PNS_environment, 1);
+    return;
   } else if (hasCommandLineOverrider) {
     SelectedPat = INSTR_PROF_PROFILE_NAME_VAR;
     PNS = PNS_command_line;