diff --git a/ChangeLog.d/ecp-window-size.txt b/ChangeLog.d/ecp-window-size.txt
new file mode 100644
index 000000000..909d4e8a4
--- /dev/null
+++ b/ChangeLog.d/ecp-window-size.txt
@@ -0,0 +1,3 @@
+Changes
+   * Reduce the default value of MBEDTLS_ECP_WINDOW_SIZE. This reduces RAM usage
+     during ECC operations at a negligible performance cost.
diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index d0e61c545..1ae51252e 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -3617,7 +3617,7 @@
 
 /* ECP options */
 //#define MBEDTLS_ECP_MAX_BITS             521 /**< Maximum bit size of groups */
-//#define MBEDTLS_ECP_WINDOW_SIZE            6 /**< Maximum window size used */
+//#define MBEDTLS_ECP_WINDOW_SIZE            4 /**< Maximum window size used */
 //#define MBEDTLS_ECP_FIXED_POINT_OPTIM      1 /**< Enable fixed-point speed-up */
 
 /* Entropy options */
diff --git a/include/mbedtls/ecp.h b/include/mbedtls/ecp.h
index b974e5984..f278d105d 100644
--- a/include/mbedtls/ecp.h
+++ b/include/mbedtls/ecp.h
@@ -258,7 +258,8 @@ mbedtls_ecp_group;
 #if !defined(MBEDTLS_ECP_WINDOW_SIZE)
 /*
  * Maximum "window" size used for point multiplication.
- * Default: 6.
+ * Default: a point where higher memory usage yields disminishing performance
+ *          returns.
  * Minimum value: 2. Maximum value: 7.
  *
  * Result is an array of at most ( 1 << ( MBEDTLS_ECP_WINDOW_SIZE - 1 ) )
@@ -275,7 +276,7 @@ mbedtls_ecp_group;
  *      224       475     475     453     398     342
  *      192       640     640     633     587     476
  */
-#define MBEDTLS_ECP_WINDOW_SIZE    6   /**< The maximum window size used. */
+#define MBEDTLS_ECP_WINDOW_SIZE    4   /**< The maximum window size used. */
 #endif /* MBEDTLS_ECP_WINDOW_SIZE */
 
 #if !defined(MBEDTLS_ECP_FIXED_POINT_OPTIM)