diff --git a/lib_com/options.h b/lib_com/options.h
old mode 100644
new mode 100755
index 2f28b8ccb330dece097261506063f6675e1beb0a..08a554d4e47820666528fb76f9a9810861101083
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -180,6 +180,7 @@
 #define NONBE_FIX_752_OSBA_MISCONFIG_MCT                      /* FhG: issue 752: misconfiguration of MCT causes crashes for coding with sampling rate under 48kHz at 256kbps*/
 #define NONBE_FIX_780_ISM_STARTS_WITH_SID                     /* VA: issue 780: fix Crash in ISM decoding when bitstream starts with an SID and output_config is not EXT */
 #define NONBE_FIX_ISM_DTX_INFINITE_CNG_ON_TRAILING_SILENCE    /* FhG: fix for cng in ISM DTX on sudden silence periods - JBM addon (issue 552) */
+#define NONBE_FIX_738_SBA_BR_SW_ASAN                       /* FhG: issue 738: fixes bug when switching to an MCT bitrate and previous frame was ACELP */
 
 /* ##################### End NON-BE switches ############################# */
 
diff --git a/lib_enc/ivas_mct_core_enc.c b/lib_enc/ivas_mct_core_enc.c
old mode 100644
new mode 100755
index bad65750ef25dd439435aa722318be88545ac464..1bb26673450e2f20f807573456729b8b8d44e75e
--- a/lib_enc/ivas_mct_core_enc.c
+++ b/lib_enc/ivas_mct_core_enc.c
@@ -337,6 +337,13 @@ void ivas_mct_core_enc(
         }
         nSubframes = ( sts[ch]->hTcxEnc->tcxMode == TCX_20 ) ? 1 : NB_DIV;
         L_subframeTCX = sts[ch]->hTcxEnc->L_frameTCX / nSubframes;
+#ifdef NONBE_FIX_738_SBA_BR_SW_ASAN
+        /* in MCT only relevant for bitrate switching from non-MCT bitrates */
+        if ( sts[ch]->last_core == ACELP_CORE )
+        {
+            L_subframeTCX += L_subframeTCX / 4;
+        }
+#endif
 
         for ( n = 0; n < nSubframes; n++ )
         {
@@ -387,6 +394,13 @@ void ivas_mct_core_enc(
         }
         nSubframes = ( st->hTcxEnc->tcxMode == TCX_20 ) ? 1 : NB_DIV;
         L_subframeTCX = st->hTcxEnc->L_frameTCX / nSubframes;
+#ifdef NONBE_FIX_738_SBA_BR_SW_ASAN
+        /* in MCT only relevant for bitrate switching from non-MCT bitrates */
+        if ( st->last_core == ACELP_CORE )
+        {
+            L_subframeTCX += L_subframeTCX / 4;
+        }
+#endif
 
         if ( ( st->hTcxEnc->tcxMode == TCX_20 ) && ( st->total_brate < HQ_96k || st->igf ) )
         {