diff --git a/src/posix/cocoa/i_main.mm b/src/posix/cocoa/i_main.mm
index 5b4ea31b7e..a5e7db2f4b 100644
--- a/src/posix/cocoa/i_main.mm
+++ b/src/posix/cocoa/i_main.mm
@@ -199,8 +199,8 @@ int OriginalMain(int argc, char** argv)
 	// Set LC_NUMERIC environment variable in case some library decides to
 	// clear the setlocale call at least this will be correct.
 	// Note that the LANG environment variable is overridden by LC_*
-	setenv("LC_NUMERIC", "C", 1);
-	setlocale(LC_ALL, "C");
+	setenv("LC_NUMERIC", "en_US.UTF-8", 1);
+	setlocale(LC_ALL, "en_US.UTF-8");
 
 	// Set reasonable default values for video settings
 
diff --git a/src/posix/sdl/i_main.cpp b/src/posix/sdl/i_main.cpp
index 5720942171..c17ed8be73 100644
--- a/src/posix/sdl/i_main.cpp
+++ b/src/posix/sdl/i_main.cpp
@@ -170,9 +170,9 @@ int main (int argc, char **argv)
 	// Set LC_NUMERIC environment variable in case some library decides to
 	// clear the setlocale call at least this will be correct.
 	// Note that the LANG environment variable is overridden by LC_*
-	setenv ("LC_NUMERIC", "C", 1);
+	setenv ("LC_NUMERIC", "en_US.UTF-8", 1);
 
-	setlocale (LC_ALL, "C");
+	setlocale (LC_ALL, "en_US.UTF-8");
 
 	if (SDL_Init (0) < 0)
 	{