diff --git a/core/inputs.go b/core/inputs.go
index b8eefb3..80728b0 100644
--- a/core/inputs.go
+++ b/core/inputs.go
@@ -1040,7 +1040,7 @@ func EvaluateToStringExpression(ctx *ExecutionState, raw string) (string, error)
 
 	strRes, ok := res.(string)
 	if !ok {
-		return "", fmt.Errorf("expression did not evaluate to a string: %T", res)
+		return fmt.Sprintf("%v", res), nil
 	}
 
 	return strRes, nil
diff --git a/tests_e2e/references/reference_expression_to_bool.sh_l27 b/tests_e2e/references/reference_expression_to_bool.sh_l27
new file mode 100644
index 0000000..959f92e
--- /dev/null
+++ b/tests_e2e/references/reference_expression_to_bool.sh_l27
@@ -0,0 +1,6 @@
+true
+true
+false
+42
+3.14
+true
diff --git a/tests_e2e/references/reference_expression_to_bool.sh_l46 b/tests_e2e/references/reference_expression_to_bool.sh_l46
new file mode 100644
index 0000000..8d3ac80
--- /dev/null
+++ b/tests_e2e/references/reference_expression_to_bool.sh_l46
@@ -0,0 +1,6 @@
+false
+true
+false
+42
+3.14
+true
diff --git a/tests_e2e/scripts/expression_to_bool.act b/tests_e2e/scripts/expression_to_bool.act
new file mode 100644
index 0000000..ec41683
--- /dev/null
+++ b/tests_e2e/scripts/expression_to_bool.act
@@ -0,0 +1,169 @@
+editor:
+  version:
+    created: v1.58.0
+entry: start
+type: standard
+nodes:
+  - id: start
+    type: core/start@v1
+    position:
+      x: 20
+      y: 10
+  - id: const-starts-with
+    type: core/const-string@v1
+    position:
+      x: 30
+      y: 210
+    inputs:
+      value: ${{ startsWith(github.ref, 'refs/tags/') }}
+  - id: const-bool-true
+    type: core/const-string@v1
+    position:
+      x: 310
+      y: 280
+    inputs:
+      value: ${{ true }}
+  - id: const-bool-false
+    type: core/const-string@v1
+    position:
+      x: 590
+      y: 350
+    inputs:
+      value: ${{ false }}
+  - id: const-int
+    type: core/const-string@v1
+    position:
+      x: 880
+      y: 420
+    inputs:
+      value: ${{ 42 }}
+  - id: const-float
+    type: core/const-string@v1
+    position:
+      x: 1160
+      y: 490
+    inputs:
+      value: ${{ 3.14 }}
+  - id: const-comparison
+    type: core/const-string@v1
+    position:
+      x: 1440
+      y: 560
+    inputs:
+      value: ${{ 1 == 1 }}
+  - id: print-starts-with
+    type: core/print@v1
+    position:
+      x: 320
+      y: 70
+    inputs:
+      values[0]: null
+  - id: print-bool-true
+    type: core/print@v1
+    position:
+      x: 610
+      y: 140
+    inputs:
+      values[0]: null
+  - id: print-bool-false
+    type: core/print@v1
+    position:
+      x: 890
+      y: 210
+    inputs:
+      values[0]: null
+  - id: print-int
+    type: core/print@v1
+    position:
+      x: 1170
+      y: 280
+    inputs:
+      values[0]: null
+  - id: print-float
+    type: core/print@v1
+    position:
+      x: 1460
+      y: 350
+    inputs:
+      values[0]: null
+  - id: print-comparison
+    type: core/print@v1
+    position:
+      x: 1730
+      y: 420
+    inputs:
+      values[0]: null
+connections:
+  - src:
+      node: const-starts-with
+      port: result
+    dst:
+      node: print-starts-with
+      port: values[0]
+  - src:
+      node: const-bool-true
+      port: result
+    dst:
+      node: print-bool-true
+      port: values[0]
+  - src:
+      node: const-bool-false
+      port: result
+    dst:
+      node: print-bool-false
+      port: values[0]
+  - src:
+      node: const-int
+      port: result
+    dst:
+      node: print-int
+      port: values[0]
+  - src:
+      node: const-float
+      port: result
+    dst:
+      node: print-float
+      port: values[0]
+  - src:
+      node: const-comparison
+      port: result
+    dst:
+      node: print-comparison
+      port: values[0]
+executions:
+  - src:
+      node: start
+      port: exec
+    dst:
+      node: print-starts-with
+      port: exec
+  - src:
+      node: print-starts-with
+      port: exec
+    dst:
+      node: print-bool-true
+      port: exec
+  - src:
+      node: print-bool-true
+      port: exec
+    dst:
+      node: print-bool-false
+      port: exec
+  - src:
+      node: print-bool-false
+      port: exec
+    dst:
+      node: print-int
+      port: exec
+  - src:
+      node: print-int
+      port: exec
+    dst:
+      node: print-float
+      port: exec
+  - src:
+      node: print-float
+      port: exec
+    dst:
+      node: print-comparison
+      port: exec
diff --git a/tests_e2e/scripts/expression_to_bool.sh b/tests_e2e/scripts/expression_to_bool.sh
new file mode 100644
index 0000000..ecf366f
--- /dev/null
+++ b/tests_e2e/scripts/expression_to_bool.sh
@@ -0,0 +1,46 @@
+echo "Test expressions evaluating to non-string types are converted to string"
+
+TEST_NAME=expression_to_bool
+GRAPH_FILE="${ACT_GRAPH_FILES_DIR}${PATH_SEPARATOR}${TEST_NAME}.act"
+cp $GRAPH_FILE $TEST_NAME.act
+export ACT_GRAPH_FILE=$TEST_NAME.act
+export GITHUB_ACTIONS=true
+export GITHUB_WORKSPACE=$ACT_GRAPH_FILES_DIR
+export GITHUB_EVENT_NAME=push
+export GITHUB_REF=refs/tags/v1.0.0
+
+# here run only the printed values (no info output)
+ACTUAL=$(ACT_LOGLEVEL=verbose ACT_NOCOLOR=true actrun 2>&1)
+
+EXPECTED=$(printf "true\ntrue\nfalse\n42\n3.14\ntrue")
+
+if [ "$ACTUAL" = "$EXPECTED" ]; then
+  echo "PASS"
+else
+  echo "FAIL"
+  echo "expected:"
+  echo "$EXPECTED"
+  echo "actual:"
+  echo "$ACTUAL"
+fi
+
+#! test echo "$ACTUAL"
+
+# now test with a branch ref, only startsWith changes to false
+export GITHUB_REF=refs/heads/main
+
+ACTUAL=$(ACT_LOGLEVEL=verbose ACT_NOCOLOR=true actrun 2>&1)
+
+EXPECTED=$(printf "false\ntrue\nfalse\n42\n3.14\ntrue")
+
+if [ "$ACTUAL" = "$EXPECTED" ]; then
+  echo "PASS"
+else
+  echo "FAIL"
+  echo "expected:"
+  echo "$EXPECTED"
+  echo "actual:"
+  echo "$ACTUAL"
+fi
+
+#! test echo "$ACTUAL"