diff --git a/src/backend/utils/adt/float.c b/src/backend/utils/adt/float.c
index 6522c08..99725bf 100644
--- a/src/backend/utils/adt/float.c
+++ b/src/backend/utils/adt/float.c
@@ -1573,7 +1573,7 @@ dpow(PG_FUNCTION_ARGS)
 	 */
 	errno = 0;
 	result = pow(arg1, arg2);
-	if (errno == EDOM && isnan(result))
+	if (errno == EDOM && isnan(result) && !(isnan(arg1) || isnan(arg2)))
 	{
 		if ((fabs(arg1) > 1 && arg2 >= 0) || (fabs(arg1) < 1 && arg2 < 0))
 			/* The sign of Inf is not significant in this case. */
diff --git a/src/test/regress/expected/float8.out b/src/test/regress/expected/float8.out
index 20c985e..6d7cdc3 100644
--- a/src/test/regress/expected/float8.out
+++ b/src/test/regress/expected/float8.out
@@ -340,6 +340,24 @@ SELECT power(float8 '144', float8 '0.5');
     12
 (1 row)
 
+SELECT power(float8 'NaN', float8 '0.5');
+ power 
+-------
+   NaN
+(1 row)
+
+SELECT power(float8 '144', float8 'NaN');
+ power 
+-------
+   NaN
+(1 row)
+
+SELECT power(float8 'NaN', float8 'NaN');
+ power 
+-------
+   NaN
+(1 row)
+
 -- take exp of ln(f.f1)
 SELECT '' AS three, f.f1, exp(ln(f.f1)) AS exp_ln_f1
    FROM FLOAT8_TBL f
diff --git a/src/test/regress/sql/float8.sql b/src/test/regress/sql/float8.sql
index 215e7a4..dca90f7 100644
--- a/src/test/regress/sql/float8.sql
+++ b/src/test/regress/sql/float8.sql
@@ -108,6 +108,9 @@ SELECT '' AS three, f.f1, |/f.f1 AS sqrt_f1
 
 -- power
 SELECT power(float8 '144', float8 '0.5');
+SELECT power(float8 'NaN', float8 '0.5');
+SELECT power(float8 '144', float8 'NaN');
+SELECT power(float8 'NaN', float8 'NaN');
 
 -- take exp of ln(f.f1)
 SELECT '' AS three, f.f1, exp(ln(f.f1)) AS exp_ln_f1