diff --git a/libavcodec/h263.h b/libavcodec/h263.h
index 1a3c85e22e..0c11514786 100644
--- a/libavcodec/h263.h
+++ b/libavcodec/h263.h
@@ -59,8 +59,8 @@ extern RLTable rl_intra_aic;
 
 extern const uint16_t h263_format[8][2];
 extern const uint8_t modified_quant_tab[2][32];
-extern uint16_t ff_mba_max[6];
-extern uint8_t ff_mba_length[7];
+extern const uint16_t ff_mba_max[6];
+extern const uint8_t ff_mba_length[7];
 
 extern uint8_t ff_h263_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];
 
diff --git a/libavcodec/h263data.h b/libavcodec/h263data.h
index 81e3ddd2e0..907eae2a65 100644
--- a/libavcodec/h263data.h
+++ b/libavcodec/h263data.h
@@ -264,11 +264,11 @@ const uint8_t ff_h263_chroma_qscale_table[32]={
     0, 1, 2, 3, 4, 5, 6, 6, 7, 8, 9, 9,10,10,11,11,12,12,12,13,13,13,14,14,14,14,14,15,15,15,15,15
 };
 
-uint16_t ff_mba_max[6]={
+const uint16_t ff_mba_max[6]={
      47,  98, 395,1583,6335,9215
 };
 
-uint8_t ff_mba_length[7]={
+const uint8_t ff_mba_length[7]={
       6,   7,   9,  11,  13,  14,  14
 };