diff --git a/check/features.frm b/check/features.frm
index 0df0e2920..55f8317e0 100644
--- a/check/features.frm
+++ b/check/features.frm
@@ -3190,6 +3190,27 @@ assert stdout =~ exact_pattern(<<'EOF')
 ~~~
 EOF
 *--#] ZeroUnchanged :
+*--#[ tablebase_dirty_blocks :
+CTable,sparse f(1);
+#do i = 1,1030
+  Fill f(`i') = `i';
+#enddo
+.sort
+TableBase "dirty-blocks.tbl" create;
+TableBase "dirty-blocks.tbl" addto f;
+.end
+CTable,sparse f(1);
+TableBase "dirty-blocks.tbl" open;
+TableBase "dirty-blocks.tbl" enter;
+.sort
+Local F = f(1)+f(1024)+f(1025)+f(1030);
+Apply;
+Print;
+.end
+#pend_if mpi?
+assert succeeded?
+assert result("F") =~ expr("3080")
+*--#] tablebase_dirty_blocks :
 *--#[ tablebase_ro_1 :
 Table,sparse,no1fill(1);
 Fill no1fill(1) = 1;
diff --git a/sources/declare.h b/sources/declare.h
index 8056b656d..30f269a30 100644
--- a/sources/declare.h
+++ b/sources/declare.h
@@ -1379,6 +1379,7 @@ extern void   convertnamesblock(NAMESBLOCK *,NAMESBLOCK *,int);
 extern void   convertiniinfo(INIINFO *,INIINFO *,int);
 extern int    ReadIndex(DBASE *);
 extern int    WriteIndexBlock(DBASE *,MLONG);
+extern int    FlushDirtyIndexBlocks(DBASE *);
 extern int    WriteNamesBlock(DBASE *,MLONG);
 extern int    WriteIndex(DBASE *);
 extern int    WriteIniInfo(DBASE *);
diff --git a/sources/minos.c b/sources/minos.c
index bd1402a3e..43ec49adb 100644
--- a/sources/minos.c
+++ b/sources/minos.c
@@ -415,9 +415,11 @@ int WriteIndexBlock(DBASE *d,MLONG num)
 /* INTERNAL_ERROR_EXCL_STOP */
 	}
 	fseek(d->handle,d->iblocks[num]->position,SEEK_SET);
+	d->iblocks[num]->flags &= MCLEANFLAG;
 	convertblock(d->iblocks[num],&scratchblock,TODISK);
 	if ( minoswrite(d->handle,(char *)(&scratchblock),sizeof(INDEXBLOCK)) ) {
 /* INTERNAL_ERROR_EXCL_START */
+		d->iblocks[num]->flags |= MDIRTYFLAG;
 		MesPrint("!>Error while writing an index block in file %s\n",d->name);
 		MesPrint("File may be unreliable now\n");
 		return(-1);
@@ -428,6 +430,22 @@ int WriteIndexBlock(DBASE *d,MLONG num)
 
 /*
   	#] WriteIndexBlock : 
+  	#[ FlushDirtyIndexBlocks :
+*/
+
+int FlushDirtyIndexBlocks(DBASE *d)
+{
+	MLONG i;
+	for ( i = 0; i < d->info.numberofindexblocks; i++ ) {
+		if ( ( d->iblocks[i]->flags & MDIRTYFLAG ) != 0 ) {
+			if ( WriteIndexBlock(d,i) ) return(-1);
+		}
+	}
+	return(0);
+}
+
+/*
+  	#] FlushDirtyIndexBlocks :
   	#[ WriteNamesBlock :
 */
 
@@ -715,7 +733,7 @@ DBASE *NewDbase(char *name,MLONG number)
 		else d->iblocks[i]->previousblock = -1;
 		d->iblocks[i]->position = ftell(f);
 		// Initialise, to keep valgrind happy
-		d->iblocks[i]->flags = -1;
+		d->iblocks[i]->flags = 0;
 /*----------change 10-feb-2003 */
 /*
 			Zero things properly. We don't want garbage in the file.
@@ -1153,6 +1171,7 @@ int AddToIndex(DBASE *d,MLONG number)
 			}
 			if ( i > 0 ) ib[i]->previousblock = ib[i-1]->position;
 			else ib[i]->previousblock = -1;
+			ib[i]->flags = 0;
 /*
 			Zero things properly. We don't want garbage in the file.
 */
@@ -1337,7 +1356,8 @@ int WriteObject(DBASE *d,MLONG tablenumber,char *arguments,char *rhs,MLONG numbe
 #else
 	obj->uncompressed = 0;
 #endif
-	return(WriteIndexBlock(d,j));
+	d->iblocks[j]->flags |= MDIRTYFLAG;
+	return(0);
 }
 
 /*
diff --git a/sources/tables.c b/sources/tables.c
index 5dc1cf1e7..96a991ab0 100644
--- a/sources/tables.c
+++ b/sources/tables.c
@@ -813,7 +813,7 @@ int CoTBaddto(UBYTE *s)
 	TABLES T = 0;
 	MLONG basenumber;
 	LONG x;
-	int i, j, error = 0, sum;
+	int i, j, error = 0, sum, writeini = 0;
 	if ( ( d = FindTB(tablebasename) ) == 0 ) {
 		MesPrint("&No open tablebase with the name %s",tablebasename);
 		return(-1);
@@ -854,7 +854,7 @@ int CoTBaddto(UBYTE *s)
 			  ParseSignedNumber(x,s);
 		      if ( FG.cTable[s[-1]] != 1 || ( *s != ',' && *s != ')' ) ) {
 				MesPrint("&Table arguments in TableBase addto statement should be numbers");
-				return(1);
+				goto tableabort;
 			  }
 			  *w++ = x;
 			  if ( *s == ')' ) break;
@@ -956,17 +956,18 @@ int CoTBaddto(UBYTE *s)
 		}
 		while ( *s == ',' || *s == ' ' || *s == '\t' ) s++;
 	}
-	if ( WriteIniInfo(d) ) goto tableabort;
+	writeini = 1;
+tablefinish:;
+	if ( FlushDirtyIndexBlocks(d) ) error = 1;
+	if ( writeini && WriteIniInfo(d) ) error = 1;
 	M_free(AO.DollarOutBuffer,"DollarOutBuffer");
 	AO.DollarOutBuffer = 0;
 	AO.DollarOutSizeBuffer = 0;
+	AO.OutInBuffer = 0;
 	return(error);	
 tableabort:;
-	M_free(AO.DollarOutBuffer,"DollarOutBuffer");
-	AO.DollarOutBuffer = 0;
-	AO.DollarOutSizeBuffer = 0;
-	AO.OutInBuffer = 0;
-	return(1);
+	error = 1;
+	goto tablefinish;
 }
 
 /*