diff --git a/tweed5-default-extensions/src/main/java/de/siphalor/tweed5/defaultextensions/validation/api/validators/NonNullValidator.java b/tweed5-default-extensions/src/main/java/de/siphalor/tweed5/defaultextensions/validation/api/validators/NonNullValidator.java
new file mode 100644
index 0000000..c3b8ab8
--- /dev/null
+++ b/tweed5-default-extensions/src/main/java/de/siphalor/tweed5/defaultextensions/validation/api/validators/NonNullValidator.java
@@ -0,0 +1,27 @@
+package de.siphalor.tweed5.defaultextensions.validation.api.validators;
+
+import de.siphalor.tweed5.core.api.entry.ConfigEntry;
+import de.siphalor.tweed5.defaultextensions.validation.api.ConfigEntryValidator;
+import de.siphalor.tweed5.defaultextensions.validation.api.result.ValidationIssue;
+import de.siphalor.tweed5.defaultextensions.validation.api.result.ValidationIssueLevel;
+import de.siphalor.tweed5.defaultextensions.validation.api.result.ValidationResult;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Collections;
+
+public class NonNullValidator implements ConfigEntryValidator {
+	@Override
+	public <T> ValidationResult<T> validate(ConfigEntry<T> configEntry, T value) {
+		if (value == null) {
+			return ValidationResult.withIssues(null, Collections.singleton(
+					new ValidationIssue("Value must not be null", ValidationIssueLevel.ERROR)
+			));
+		}
+		return ValidationResult.ok(value);
+	}
+
+	@Override
+	public @NotNull <T> String description(ConfigEntry<T> configEntry) {
+		return "Must be set (not null).";
+	}
+}