diff --git a/checkstyle.xml b/checkstyle.xml
index 2219dec..cf551d9 100644
--- a/checkstyle.xml
+++ b/checkstyle.xml
@@ -4,6 +4,9 @@
 	"-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
 	"https://checkstyle.org/dtds/configuration_1_3.dtd">
 <module name="Checker">
+	<module name="SuppressionFilter">
+    	<property name="file" value="suppressions.xml"/>
+	</module>
 	<!-- CheckStyle settings -->
 
 	<module name="TreeWalker">
@@ -67,6 +70,7 @@
 			<property name="ignoreHashCodeMethod" value="false"/>
 			<property name="ignoreAnnotation" value="true"/>
 			<property name="ignoreFieldDeclaration" value="false"/>
+			<!-- Note: affected by /suppressions.xml -->
 		</module>
 
 		<!-- 9: Check parameter number at most 6 -->
diff --git a/suppressions.xml b/suppressions.xml
new file mode 100644
index 0000000..5935fec
--- /dev/null
+++ b/suppressions.xml
@@ -0,0 +1,10 @@
+<!DOCTYPE suppressions PUBLIC
+    "-//Checkstyle//DTD SuppressionFilter Configuration 1.2//EN"
+    "https://checkstyle.org/dtds/suppressions_1_2.dtd">
+
+<suppressions>
+  <!-- disable MagicNumber check for all tests -->
+  <suppress checks="MagicNumber"
+            files=".*[\\/]src[\\/]test[\\/].*"/>
+</suppressions>
+