diff --git a/src/test/regress/expected/hash_func.out b/src/test/regress/expected/hash_func.out
index 61c6cbbf109..8e23dc39783 100644
--- a/src/test/regress/expected/hash_func.out
+++ b/src/test/regress/expected/hash_func.out
@@ -348,7 +348,7 @@ SELECT hashfloat4('0'::float4) = hashfloat4('-0'::float4) AS t;
  t
 (1 row)
 
-SELECT hashfloat4('NaN'::float4) = hashfloat4('-NaN'::float4) AS t;
+SELECT hashfloat4('NaN'::float4) = hashfloat4(-'NaN'::float4) AS t;
  t 
 ---
  t
@@ -360,7 +360,7 @@ SELECT hashfloat8('0'::float8) = hashfloat8('-0'::float8) AS t;
  t
 (1 row)
 
-SELECT hashfloat8('NaN'::float8) = hashfloat8('-NaN'::float8) AS t;
+SELECT hashfloat8('NaN'::float8) = hashfloat8(-'NaN'::float8) AS t;
  t 
 ---
  t
diff --git a/src/test/regress/sql/hash_func.sql b/src/test/regress/sql/hash_func.sql
index 5c994f5de5e..5ad33c1f9d4 100644
--- a/src/test/regress/sql/hash_func.sql
+++ b/src/test/regress/sql/hash_func.sql
@@ -258,7 +258,7 @@ DROP TYPE hash_test_t2;
 -- Check special cases for specific data types
 --
 SELECT hashfloat4('0'::float4) = hashfloat4('-0'::float4) AS t;
-SELECT hashfloat4('NaN'::float4) = hashfloat4('-NaN'::float4) AS t;
+SELECT hashfloat4('NaN'::float4) = hashfloat4(-'NaN'::float4) AS t;
 SELECT hashfloat8('0'::float8) = hashfloat8('-0'::float8) AS t;
-SELECT hashfloat8('NaN'::float8) = hashfloat8('-NaN'::float8) AS t;
+SELECT hashfloat8('NaN'::float8) = hashfloat8(-'NaN'::float8) AS t;
 SELECT hashfloat4('NaN'::float4) = hashfloat8('NaN'::float8) AS t;