diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/TypeCoercion.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/TypeCoercion.scala
index 6082c58e2c53..a78e1c98e89d 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/TypeCoercion.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/TypeCoercion.scala
@@ -362,6 +362,8 @@ object TypeCoercion {
       case Average(e @ StringType()) => Average(Cast(e, DoubleType))
       case StddevPop(e @ StringType()) => StddevPop(Cast(e, DoubleType))
       case StddevSamp(e @ StringType()) => StddevSamp(Cast(e, DoubleType))
+      case UnaryMinus(e @ StringType()) => UnaryMinus(Cast(e, DoubleType))
+      case UnaryPositive(e @ StringType()) => UnaryPositive(Cast(e, DoubleType))
       case VariancePop(e @ StringType()) => VariancePop(Cast(e, DoubleType))
       case VarianceSamp(e @ StringType()) => VarianceSamp(Cast(e, DoubleType))
       case Skewness(e @ StringType()) => Skewness(Cast(e, DoubleType))
diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/analysis/ExpressionTypeCheckingSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/analysis/ExpressionTypeCheckingSuite.scala
index 2239bf815de7..30459f173ab5 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/analysis/ExpressionTypeCheckingSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/analysis/ExpressionTypeCheckingSuite.scala
@@ -56,7 +56,6 @@ class ExpressionTypeCheckingSuite extends SparkFunSuite {
   }
 
   test("check types for unary arithmetic") {
-    assertError(UnaryMinus('stringField), "(numeric or calendarinterval) type")
     assertError(BitwiseNot('stringField), "requires integral type")
   }
 
diff --git a/sql/core/src/test/resources/sql-tests/inputs/operators.sql b/sql/core/src/test/resources/sql-tests/inputs/operators.sql
index a1e8a32ed8f6..be666a85f238 100644
--- a/sql/core/src/test/resources/sql-tests/inputs/operators.sql
+++ b/sql/core/src/test/resources/sql-tests/inputs/operators.sql
@@ -88,3 +88,6 @@ select OCTET_LENGTH('abc');
 
 -- abs
 select abs(-3.13), abs('-2.19');
+
+-- positive/negative
+select positive('-1.11'), positive(-1.11), negative('-1.11'), negative(-1.11);
diff --git a/sql/core/src/test/resources/sql-tests/results/operators.sql.out b/sql/core/src/test/resources/sql-tests/results/operators.sql.out
index eac3080bec67..451583c0b836 100644
--- a/sql/core/src/test/resources/sql-tests/results/operators.sql.out
+++ b/sql/core/src/test/resources/sql-tests/results/operators.sql.out
@@ -1,5 +1,5 @@
 -- Automatically generated by SQLQueryTestSuite
--- Number of queries: 55
+-- Number of queries: 56
 
 
 -- !query 0
@@ -452,3 +452,11 @@ select abs(-3.13), abs('-2.19')
 struct<abs(-3.13):decimal(3,2),abs(CAST(-2.19 AS DOUBLE)):double>
 -- !query 54 output
 3.13	2.19
+
+
+-- !query 55
+select positive('-1.11'), positive(-1.11), negative('-1.11'), negative(-1.11)
+-- !query 55 schema
+struct<(+ CAST(-1.11 AS DOUBLE)):double,(+ -1.11):decimal(3,2),(- CAST(-1.11 AS DOUBLE)):double,(- -1.11):decimal(3,2)>
+-- !query 55 output
+-1.11	-1.11	1.11	1.11