diff --git a/src/core/runtime.d b/src/core/runtime.d
index c569d74efd1..dc9656db2fc 100644
--- a/src/core/runtime.d
+++ b/src/core/runtime.d
@@ -42,6 +42,7 @@ private
     extern (C) TraceHandler rt_getTraceHandler();
 
     alias void delegate( Throwable ) ExceptionHandler;
+    extern (C) void _d_print_throwable(Throwable t);
 
     extern (C) void* thread_stackBottom();
 
@@ -380,12 +381,6 @@ extern (C) bool runModuleUnitTests()
 
     if( Runtime.sm_moduleUnitTester is null )
     {
-        void printErr(in char[] buf)
-        {
-            import core.stdc.stdio : fprintf, stderr;
-            fprintf(stderr, "%.*s", cast(int)buf.length, buf.ptr);
-        }
-
         size_t failed = 0;
         foreach( m; ModuleInfo )
         {
@@ -401,7 +396,7 @@ extern (C) bool runModuleUnitTests()
                     }
                     catch( Throwable e )
                     {
-                        e.toString(&printErr); printErr("\n");
+                        _d_print_throwable(e);
                         failed++;
                     }
                 }
diff --git a/src/rt/dmain2.d b/src/rt/dmain2.d
index 77edcd592b5..e1310cc0fbf 100644
--- a/src/rt/dmain2.d
+++ b/src/rt/dmain2.d
@@ -175,7 +175,7 @@ extern (C) int rt_init()
     catch (Throwable t)
     {
         _initCount = 0;
-        printThrowable(t);
+        _d_print_throwable(t);
     }
     _STD_critical_term();
     _STD_monitor_staticdtor();
@@ -201,7 +201,7 @@ extern (C) int rt_term()
     }
     catch (Throwable t)
     {
-        printThrowable(t);
+        _d_print_throwable(t);
     }
     finally
     {
@@ -398,7 +398,7 @@ extern (C) int _d_run_main(int argc, char **argv, MainFunc mainFunc)
             }
             catch (Throwable t)
             {
-                printThrowable(t);
+                _d_print_throwable(t);
                 result = EXIT_FAILURE;
             }
         }
@@ -460,7 +460,7 @@ private void formatThrowable(Throwable t, void delegate(in char[] s) nothrow sin
     }
 }
 
-private void printThrowable(Throwable t)
+extern (C) void _d_print_throwable(Throwable t)
 {
     // On Windows, a console may not be present to print the output to.
     // Show a message box instead.