diff --git a/core/modules/toolbar/config/schema/toolbar.schema.yml b/core/modules/toolbar/config/schema/toolbar.schema.yml
new file mode 100644
index 0000000..c0949f2
--- /dev/null
+++ b/core/modules/toolbar/config/schema/toolbar.schema.yml
@@ -0,0 +1,25 @@
+# Schema for the configuration files of the toolbar module.
+
+toolbar.settings:
+  type: mapping
+  label: 'Toolbar settings'
+  mapping:
+    breakpoints:
+      type: sequence
+      label: 'Breakpoints'
+      sequence:
+        - type: string
+
+toolbar.breakpoints:
+  type: mapping
+  label: 'Toolbar breakpoint settings'
+  mapping:
+    narrow:
+      type: string
+      label: 'Narrow'
+    standard:
+      type: string
+      label: 'Standard'
+    wide:
+      type: string
+      label: 'Wide'