diff --git a/util/test/demos/linux/linux_platform.cpp b/util/test/demos/linux/linux_platform.cpp
index b488de70a..b4dd2082b 100644
--- a/util/test/demos/linux/linux_platform.cpp
+++ b/util/test/demos/linux/linux_platform.cpp
@@ -22,6 +22,7 @@
 * THE SOFTWARE.
 ******************************************************************************/
 
+#include <stdlib.h>
 #include "test_common.h"
 
 std::string GetCWD()
@@ -48,4 +49,9 @@ std::string GetEnvVar(const char *var)
     return data;
 
   return "";
+}
+
+void tmpnam_via_mkstemp(char (&buf)[MAX_PATH])
+{
+  snprintf(buf, MAX_PATH - 1, "/tmp/rdoc_tmp/%x", rand());
 }
\ No newline at end of file
diff --git a/util/test/demos/linux/linux_platform.h b/util/test/demos/linux/linux_platform.h
index 390912ad4..cc2bc55f7 100644
--- a/util/test/demos/linux/linux_platform.h
+++ b/util/test/demos/linux/linux_platform.h
@@ -33,4 +33,8 @@
 
 #define msleep(time) usleep((time)*1000)
 
-#define EXECUTABLE_SUFFIX ""
\ No newline at end of file
+#define EXECUTABLE_SUFFIX ""
+
+#define get_tmpnam tmpnam_via_mkstemp
+
+void tmpnam_via_mkstemp(char (&buf)[MAX_PATH]);
\ No newline at end of file
diff --git a/util/test/demos/test_common.cpp b/util/test/demos/test_common.cpp
index ba2792ec1..5b8874b8c 100644
--- a/util/test/demos/test_common.cpp
+++ b/util/test/demos/test_common.cpp
@@ -300,8 +300,8 @@ std::vector<uint32_t> CompileShaderToSpv(const std::string &source_text, SPIRVTa
 
   char infile[MAX_PATH] = {};
   char outfile[MAX_PATH] = {};
-  tmpnam(infile);
-  tmpnam(outfile);
+  get_tmpnam(infile);
+  get_tmpnam(outfile);
 
   command_line += " -o ";
   command_line += outfile;
diff --git a/util/test/demos/win32/win32_platform.h b/util/test/demos/win32/win32_platform.h
index d2cadbf4d..5771db7b3 100644
--- a/util/test/demos/win32/win32_platform.h
+++ b/util/test/demos/win32/win32_platform.h
@@ -44,6 +44,8 @@ std::wstring UTF82Wide(const std::string &s);
 #define popen _popen
 #define pclose _pclose
 
+#define get_tmpnam tmpnam_s
+
 #define msleep(time) Sleep(time)
 
 #define WEXITSTATUS(code) code