diff --git a/src/backend/utils/adt/tsquery_util.c b/src/backend/utils/adt/tsquery_util.c
index 63760080b26..5c5e3444aab 100644
--- a/src/backend/utils/adt/tsquery_util.c
+++ b/src/backend/utils/adt/tsquery_util.c
@@ -289,7 +289,7 @@ QTNBinary(QTNode *in)
  * Caller must initialize *sumlen and *nnode to zeroes.
  */
 static void
-cntsize(QTNode *in, int *sumlen, int *nnode)
+cntsize(QTNode *in, size_t *sumlen, size_t *nnode)
 {
 	/* since this function recurses, it could be driven to stack overflow. */
 	check_stack_depth();
@@ -327,10 +327,17 @@ fillQT(QTN2QTState *state, QTNode *in)
 
 	if (in->valnode->type == QI_VAL)
 	{
+		size_t		distance;
+
 		memcpy(state->curitem, in->valnode, sizeof(QueryOperand));
 
 		memcpy(state->curoperand, in->word, in->valnode->qoperand.length);
-		state->curitem->qoperand.distance = state->curoperand - state->operand;
+		distance = state->curoperand - state->operand;
+		if (distance > MAXSTRPOS)
+			ereport(ERROR,
+					(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+					 errmsg("tsquery is too large")));
+		state->curitem->qoperand.distance = distance;
 		state->curoperand[in->valnode->qoperand.length] = '\0';
 		state->curoperand += in->valnode->qoperand.length + 1;
 		state->curitem++;
@@ -364,7 +371,7 @@ QTN2QT(QTNode *in)
 {
 	TSQuery		out;
 	int			len;
-	int			sumlen = 0,
+	size_t		sumlen = 0,
 				nnode = 0;
 	QTN2QTState state;
 
diff --git a/src/include/tsearch/ts_type.h b/src/include/tsearch/ts_type.h
index c102ff5ad4f..63029f06096 100644
--- a/src/include/tsearch/ts_type.h
+++ b/src/include/tsearch/ts_type.h
@@ -250,7 +250,8 @@ typedef TSQueryData *TSQuery;
  */
 #define COMPUTESIZE(size, lenofoperand) ( HDRSIZETQ + (size) * sizeof(QueryItem) + (lenofoperand) )
 #define TSQUERY_TOO_BIG(size, lenofoperand) \
-	((size) > (MaxAllocSize - HDRSIZETQ - (lenofoperand)) / sizeof(QueryItem))
+	((size_t) (lenofoperand) > MaxAllocSize - HDRSIZETQ || \
+	 (size) > (MaxAllocSize - HDRSIZETQ - (lenofoperand)) / sizeof(QueryItem))
 
 /* Returns a pointer to the first QueryItem in a TSQuery */
 #define GETQUERY(x)  ((QueryItem*)( (char*)(x)+HDRSIZETQ ))