diff --git a/internal/runconfig/runconfig.go b/internal/runconfig/runconfig.go
index a695f94..b7cf301 100644
--- a/internal/runconfig/runconfig.go
+++ b/internal/runconfig/runconfig.go
@@ -26,6 +26,10 @@ import (
 	errors "golang.org/x/xerrors"
 )
 
+const (
+	defaultShell = "/bin/sh -e"
+)
+
 func genRuntime(c *config.Config, ce *config.Runtime, variables map[string]string) *rstypes.Runtime {
 	containers := []*rstypes.Container{}
 	for _, cc := range ce.Containers {
@@ -206,6 +210,10 @@ func GenRunConfigTasks(uuid util.UUIDGenerator, c *config.Config, runName string
 			DockerRegistriesAuth: make(map[string]rstypes.DockerRegistryAuth),
 		}
 
+		if t.Shell == "" {
+			t.Shell = defaultShell
+		}
+
 		if c.DockerRegistriesAuth != nil {
 			for regname, auth := range c.DockerRegistriesAuth {
 				t.DockerRegistriesAuth[regname] = rstypes.DockerRegistryAuth{
diff --git a/internal/runconfig/runconfig_test.go b/internal/runconfig/runconfig_test.go
index 92f7bd4..39ee913 100644
--- a/internal/runconfig/runconfig_test.go
+++ b/internal/runconfig/runconfig_test.go
@@ -801,6 +801,7 @@ func TestGenRunConfig(t *testing.T) {
 							},
 						},
 					},
+					Shell: "/bin/sh -e",
 					Environment: map[string]string{
 						"ENV01":             "ENV01",
 						"ENVFROMVARIABLE01": "VARVALUE01",
@@ -876,6 +877,7 @@ func TestGenRunConfig(t *testing.T) {
 							},
 						},
 					},
+					Shell:       "/bin/sh -e",
 					Environment: map[string]string{},
 					Steps: rstypes.Steps{
 						&rstypes.RunStep{BaseStep: rstypes.BaseStep{Type: "run", Name: "command01"}, Command: "command01", Environment: map[string]string{}},
@@ -973,6 +975,7 @@ func TestGenRunConfig(t *testing.T) {
 							},
 						},
 					},
+					Shell:       "/bin/sh -e",
 					Environment: map[string]string{},
 					Steps: rstypes.Steps{
 						&rstypes.RunStep{BaseStep: rstypes.BaseStep{Type: "run", Name: "command01"}, Command: "command01", Environment: map[string]string{}},
diff --git a/internal/services/executor/executor.go b/internal/services/executor/executor.go
index c60d2a7..be400e3 100644
--- a/internal/services/executor/executor.go
+++ b/internal/services/executor/executor.go
@@ -109,6 +109,8 @@ func (e *Executor) doRunStep(ctx context.Context, s *types.RunStep, t *types.Exe
 	}
 	defer outf.Close()
 
+	// TODO(sgotti) this line is used only for old runconfig versions that don't
+	// set a task default shell in the runconfig
 	shell := defaultShell
 	if t.Shell != "" {
 		shell = t.Shell