diff --git a/lib_com/edct_fx.c b/lib_com/edct_fx.c
index 8d77da13a7eb7df052bb309302e7f19bdef81432..b1e2a7dd9b76719cec5ef06815655c249d617237 100644
--- a/lib_com/edct_fx.c
+++ b/lib_com/edct_fx.c
@@ -592,11 +592,12 @@ void edxt_fx(
     const UWord16 synthesis   /* i  : nonzero for inverse Q0*/
 )
 {
-    Word16 k, m, fac;
+    Word16 k, m, fac, hdrm, tmp = 0;
     const Word16 *cosPtr, *sinPtr;
     Word16 n;
     n = 0;
     move16();
+    move16();
     cosPtr = NULL;
     sinPtr = NULL;
     IF( EQ_16( length, 512 ) )
@@ -735,7 +736,23 @@ void edxt_fx(
 
             IF( EQ_16( length, 512 ) )
             {
+                /* Scaling down re and im buffers to avoid overflow in DoRTFTn_fx if the minimum headroom is less than 4 bits */
+                hdrm = s_min( L_norm_arr( re, 512 ), L_norm_arr( im, 512 ) );
+                IF( LT_16( hdrm, 4 ) )
+                {
+                    tmp = sub( hdrm, 4 );
+                    scale_sig32( re, 512, tmp );
+                    scale_sig32( im, 512, tmp );
+                }
+
                 DoRTFTn_fx( re, im, 512 );
+
+                IF( LT_16( hdrm, 4 ) )
+                {
+                    tmp = negate( tmp );
+                    scale_sig32( re, 512, tmp );
+                    scale_sig32( im, 512, tmp );
+                }
             }
             ELSE /* fft() doesn't support 512 */
             {
@@ -831,7 +848,23 @@ void edxt_fx(
 
             IF( EQ_16( length, 512 ) )
             {
+                /* Scaling down re and im buffers to avoid overflow in DoRTFTn_fx if the minimum headroom is less than 4 bits */
+                hdrm = s_min( L_norm_arr( re, 512 ), L_norm_arr( im, 512 ) );
+                IF( LT_16( hdrm, 4 ) )
+                {
+                    tmp = sub( hdrm, 4 );
+                    scale_sig32( re, 512, tmp );
+                    scale_sig32( im, 512, tmp );
+                }
+
                 DoRTFTn_fx( re, im, 512 );
+
+                IF( LT_16( hdrm, 4 ) )
+                {
+                    tmp = negate( tmp );
+                    scale_sig32( re, 512, tmp );
+                    scale_sig32( im, 512, tmp );
+                }
             }
             ELSE /* fft() doesn't support 512 */
             {