diff --git a/enginetest/queries/queries.go b/enginetest/queries/queries.go
index 39b6bbb215..e4e8d2e605 100644
--- a/enginetest/queries/queries.go
+++ b/enginetest/queries/queries.go
@@ -8737,6 +8737,24 @@ from typestable`,
 			{3, "third row"},
 		},
 	},
+	{
+		Query: "select case when 1 then 59 + 81 / 1 end;",
+		Expected: []sql.Row{
+			{"140.0000"},
+		},
+	},
+	{
+		Query: "select case 1 when 2 then null else (6 * 2) / 1 end;",
+		Expected: []sql.Row{
+			{"12.0000"},
+		},
+	},
+	{
+		Query: "select case 1 when 1 then (6 * 2) / 1 when 2 then null else null end;",
+		Expected: []sql.Row{
+			{"12.0000"},
+		},
+	},
 }
 
 var KeylessQueries = []QueryTest{
diff --git a/sql/expression/case.go b/sql/expression/case.go
index 1e5f69db00..ea43a6f647 100644
--- a/sql/expression/case.go
+++ b/sql/expression/case.go
@@ -180,8 +180,12 @@ func (c *Case) Eval(ctx *sql.Context, row sql.Row) (interface{}, error) {
 			if err != nil {
 				return nil, err
 			}
-			ret, _, err := t.Convert(bval)
-			return ret, err
+			// When unable to convert to the type of the case, return the original value
+			// A common error here is "Out of bounds value for decimal type"
+			if ret, _, err := t.Convert(bval); err == nil {
+				return ret, nil
+			}
+			return bval, nil
 		}
 	}
 
@@ -190,8 +194,12 @@ func (c *Case) Eval(ctx *sql.Context, row sql.Row) (interface{}, error) {
 		if err != nil {
 			return nil, err
 		}
-		ret, _, err := t.Convert(val)
-		return ret, err
+		// When unable to convert to the type of the case, return the original value
+		// A common error here is "Out of bounds value for decimal type"
+		if ret, _, err := t.Convert(val); err == nil {
+			return ret, nil
+		}
+		return val, nil
 
 	}