diff --git a/src/config/type/Regexp.ts b/src/config/type/Regexp.ts
index 47f2317..6879556 100644
--- a/src/config/type/Regexp.ts
+++ b/src/config/type/Regexp.ts
@@ -3,7 +3,7 @@ import { isNil } from 'lodash';
 
 import { InvalidArgumentError } from '../../error/InvalidArgumentError';
 
-export const REGEXP_REGEXP = /\/(.*)\/([gimuy]*)/;
+export const REGEXP_REGEXP = /^\/(.+)\/([gimsuy]*)$/;
 
 export const regexpType = new YamlType('!regexp', {
   kind: 'scalar',
diff --git a/test/config/type/TestRegexp.ts b/test/config/type/TestRegexp.ts
index 9720197..d7c998c 100644
--- a/test/config/type/TestRegexp.ts
+++ b/test/config/type/TestRegexp.ts
@@ -16,4 +16,12 @@ describeLeaks('regexp config type', async () => {
   itLeaks('should not match bare strings', async () => {
     expect(regexpType.resolve('foo')).to.equal(false);
   });
+
+  itLeaks('should not match invalid flags', async () => {
+    expect(regexpType.resolve('/foo/notrealflags')).to.equal(false);
+  });
+
+  itLeaks('should not match regex embedded in a longer string', async () => {
+    expect(regexpType.resolve('some/regex/with-padding')).to.equal(false);
+  });
 });