diff --git a/MMM-GoogleCalendar.js b/MMM-GoogleCalendar.js
index cde39b6..0e38e1c 100644
--- a/MMM-GoogleCalendar.js
+++ b/MMM-GoogleCalendar.js
@@ -525,7 +525,7 @@ Module.register("MMM-GoogleCalendar", {
     // if those are common, as it avoids the listContainsEvent check for duplicates.
 
     // Filter based on `excludedEvents` config
-  if (this.config.excludedEvents?.length && this.config.excludedEvents.includes(event.summary)) {
+  if (this.config.excludedEvents?.length && this.isEventExcluded(event.summary)) {
     Log.debug(`Event ${event.id} ('${event.summary}') filtered due to excludedEvents settings.`);
     return true;
   }
@@ -552,6 +552,54 @@ Module.register("MMM-GoogleCalendar", {
   return false; // Event should not be filtered out
   },
 
+  /**
+   * Determines whether an event title matches any `excludedEvents` filter.
+   *
+   * Mirrors the default MagicMirror calendar module: each entry may be a plain
+   * string (case-insensitive substring match) or an object
+   * `{ filterBy, caseSensitive, regex }`. Previously this used an exact,
+   * case-sensitive full-title equality check, so partial filters such as
+   * "Birthday" never matched "John's Birthday" (issue #55).
+   *
+   * @param {string} title The event summary/title to test.
+   * @returns {boolean} True if the title matches an exclusion filter.
+   */
+  isEventExcluded: function (title) {
+    if (typeof title !== "string") {
+      return false;
+    }
+
+    for (const filter of this.config.excludedEvents) {
+      let pattern = filter;
+      let caseSensitive = false;
+      let useRegex = false;
+
+      if (filter && typeof filter === "object") {
+        pattern = filter.filterBy;
+        caseSensitive = !!filter.caseSensitive;
+        useRegex = !!filter.regex;
+      }
+
+      if (typeof pattern !== "string" || pattern === "") {
+        continue;
+      }
+
+      if (useRegex) {
+        if (new RegExp(pattern, caseSensitive ? "" : "i").test(title)) {
+          return true;
+        }
+      } else if (caseSensitive) {
+        if (title.includes(pattern)) {
+          return true;
+        }
+      } else if (title.toLowerCase().includes(pattern.toLowerCase())) {
+        return true;
+      }
+    }
+
+    return false;
+  },
+
   fetchCalendars: function () {
     this.config.calendars.forEach((calendar) => {
       if (!calendar.calendarID) {
diff --git a/__tests__/MMM-GoogleCalendar.test.js b/__tests__/MMM-GoogleCalendar.test.js
index b2fd0cd..01a0b19 100644
--- a/__tests__/MMM-GoogleCalendar.test.js
+++ b/__tests__/MMM-GoogleCalendar.test.js
@@ -116,5 +116,45 @@ describe('MMM-GoogleCalendar', () => {
     });
   });
 
+  describe('isEventExcluded', () => {
+    test('matches a case-insensitive substring (issue #55)', () => {
+      GCal.config.excludedEvents = ['Birthday'];
+      expect(GCal.isEventExcluded("John's Birthday")).toBe(true);
+      expect(GCal.isEventExcluded('my birthday party')).toBe(true);
+    });
+
+    test('does not match unrelated titles', () => {
+      GCal.config.excludedEvents = ['Birthday'];
+      expect(GCal.isEventExcluded('Team standup')).toBe(false);
+    });
+
+    test('still matches an exact full title (backwards compatible)', () => {
+      GCal.config.excludedEvents = ['Lunch'];
+      expect(GCal.isEventExcluded('Lunch')).toBe(true);
+    });
+
+    test('object form with caseSensitive only matches exact case', () => {
+      GCal.config.excludedEvents = [{ filterBy: 'Standup', caseSensitive: true }];
+      expect(GCal.isEventExcluded('Daily Standup')).toBe(true);
+      expect(GCal.isEventExcluded('daily standup')).toBe(false);
+    });
+
+    test('object form with regex matches a pattern', () => {
+      GCal.config.excludedEvents = [{ filterBy: '^\\[private\\]', regex: true }];
+      expect(GCal.isEventExcluded('[private] dentist')).toBe(true);
+      expect(GCal.isEventExcluded('not [private]')).toBe(false);
+    });
+
+    test('returns false for a private event with no summary', () => {
+      GCal.config.excludedEvents = ['Birthday'];
+      expect(GCal.isEventExcluded(undefined)).toBe(false);
+    });
+
+    test('ignores empty/invalid filter entries', () => {
+      GCal.config.excludedEvents = ['', { filterBy: '' }, {}];
+      expect(GCal.isEventExcluded('anything')).toBe(false);
+    });
+  });
+
   // Add more describe blocks for other pure functions if identified
 });