diff --git a/src/include/lib/simplehash.h b/src/include/lib/simplehash.h
index 90dfa8a695..3d3273a6bb 100644
--- a/src/include/lib/simplehash.h
+++ b/src/include/lib/simplehash.h
@@ -156,7 +156,7 @@ SH_SCOPE	SH_TYPE *SH_CREATE(MemoryContext ctx, uint32 nelements,
 #endif
 SH_SCOPE void SH_DESTROY(SH_TYPE * tb);
 SH_SCOPE void SH_RESET(SH_TYPE * tb);
-SH_SCOPE void SH_GROW(SH_TYPE * tb, uint32 newsize);
+SH_SCOPE void SH_GROW(SH_TYPE * tb, uint64 newsize);
 SH_SCOPE	SH_ELEMENT_TYPE *SH_INSERT(SH_TYPE * tb, SH_KEY_TYPE key, bool *found);
 SH_SCOPE	SH_ELEMENT_TYPE *SH_INSERT_HASH(SH_TYPE * tb, SH_KEY_TYPE key,
 											uint32 hash, bool *found);
@@ -232,7 +232,7 @@ SH_SCOPE void SH_STAT(SH_TYPE * tb);
  * the hashtable.
  */
 static inline void
-SH_COMPUTE_PARAMETERS(SH_TYPE * tb, uint32 newsize)
+SH_COMPUTE_PARAMETERS(SH_TYPE * tb, uint64 newsize)
 {
 	uint64		size;
 
@@ -252,11 +252,7 @@ SH_COMPUTE_PARAMETERS(SH_TYPE * tb, uint32 newsize)
 
 	/* now set size */
 	tb->size = size;
-
-	if (tb->size == SH_MAX_SIZE)
-		tb->sizemask = 0;
-	else
-		tb->sizemask = tb->size - 1;
+	tb->sizemask = (uint32) (size - 1);
 
 	/*
 	 * Compute the next threshold at which we need to grow the hash table
@@ -406,7 +402,7 @@ SH_RESET(SH_TYPE * tb)
  * performance-wise, when known at some point.
  */
 SH_SCOPE void
-SH_GROW(SH_TYPE * tb, uint32 newsize)
+SH_GROW(SH_TYPE * tb, uint64 newsize)
 {
 	uint64		oldsize = tb->size;
 	SH_ELEMENT_TYPE *olddata = tb->data;