diff --git a/libraries/tests/mbed/env/test_env.cpp b/libraries/tests/mbed/env/test_env.cpp
index 28a29f5353..33c032058e 100644
--- a/libraries/tests/mbed/env/test_env.cpp
+++ b/libraries/tests/mbed/env/test_env.cpp
@@ -1,11 +1,11 @@
 #include "test_env.h"
 
-void led_blink(PinName led) {
+void led_blink(PinName led, float delay) {
     if (led != NC) {
         DigitalOut myled(led);
         while (1) {
             myled = !myled;
-            wait(1.0);
+            wait(delay);
         }
     }
     while(1);
@@ -13,15 +13,12 @@ void led_blink(PinName led) {
 
 void notify_completion(bool success) {
     if (success) {
-        printf("{{success}}" NL );
+        printf("{{success}}" NL);
     } else {
-        printf("{{failure}}" NL );
+        printf("{{failure}}" NL);
     }
 
     printf("{{end}}" NL);
-#ifdef LED4
-    led_blink(success ? LED1 : LED4);
-#else
-    led_blink(success ? LED1 : NC);
-#endif
+    
+    led_blink(LED1, success ? 1.0 : 0.1);
 }
diff --git a/libraries/tests/mbed/env/test_env.h b/libraries/tests/mbed/env/test_env.h
index debdfc7c29..18edc9d372 100644
--- a/libraries/tests/mbed/env/test_env.h
+++ b/libraries/tests/mbed/env/test_env.h
@@ -6,7 +6,7 @@
 
 #define NL     "\n"
 
-void led_blink(void);
+void led_blink(PinName led, float delay);
 
 void notify_completion(bool success);