diff --git a/Clover/app/src/main/java/org/floens/chan/core/manager/FilterEngine.java b/Clover/app/src/main/java/org/floens/chan/core/manager/FilterEngine.java
index 6128c1ddf4..6865f52c8d 100644
--- a/Clover/app/src/main/java/org/floens/chan/core/manager/FilterEngine.java
+++ b/Clover/app/src/main/java/org/floens/chan/core/manager/FilterEngine.java
@@ -187,10 +187,6 @@ public boolean matches(Filter filter, Post.Builder post) {
 
     @AnyThread
     public boolean matches(Filter filter, boolean matchRegex, String text, boolean forceCompile) {
-        if (TextUtils.isEmpty(text)) {
-            return false;
-        }
-
         if (matchRegex) {
             Pattern pattern = null;
             if (!forceCompile) {
@@ -248,14 +244,16 @@ public Pattern compile(String rawPattern) {
             }
 
             try {
-                pattern = Pattern.compile(isRegex.group(1), flags);
+                //Don't allow an empty regex string (would match everything)
+                pattern = isRegex.group(1).length() > 0 ? Pattern.compile(isRegex.group(1), flags) : null;
             } catch (PatternSyntaxException e) {
                 return null;
             }
         } else if (rawPattern.length() >= 2 && rawPattern.charAt(0) == '"' && rawPattern.charAt(rawPattern.length() - 1) == '"') {
             // "matches an exact sentence"
             String text = escapeRegex(rawPattern.substring(1, rawPattern.length() - 1));
-            pattern = Pattern.compile(text, Pattern.CASE_INSENSITIVE);
+            //Don't allow only double quotes (would match everything)
+            pattern = rawPattern.length() != 2 ? Pattern.compile(text, Pattern.CASE_INSENSITIVE) : null;
         } else {
             String[] words = rawPattern.split(" ");
             String text = "";
@@ -268,8 +266,8 @@ public Pattern compile(String rawPattern) {
                     text += "|";
                 }
             }
-
-            pattern = Pattern.compile(text, Pattern.CASE_INSENSITIVE);
+            //Don't allow only spaces (would match everything after split)
+            pattern = !TextUtils.isEmpty(text) ? Pattern.compile(text.toString(), Pattern.CASE_INSENSITIVE) : null;
         }
 
         return pattern;
diff --git a/Clover/app/src/main/java/org/floens/chan/ui/layout/FilterLayout.java b/Clover/app/src/main/java/org/floens/chan/ui/layout/FilterLayout.java
index 57844ab4a4..9a782e5ade 100644
--- a/Clover/app/src/main/java/org/floens/chan/ui/layout/FilterLayout.java
+++ b/Clover/app/src/main/java/org/floens/chan/ui/layout/FilterLayout.java
@@ -67,7 +67,6 @@
 public class FilterLayout extends LinearLayout implements View.OnClickListener {
     private TextView typeText;
     private TextView boardsSelector;
-    private boolean patternContainerErrorShowing = false;
     private TextView pattern;
     private TextView patternPreview;
     private TextView patternPreviewStatus;
@@ -341,11 +340,7 @@ public void onClick(DialogInterface dialog, int which) {
 
     private void updateFilterValidity() {
         boolean valid = !TextUtils.isEmpty(filter.pattern) && filterEngine.compile(filter.pattern) != null;
-
-        if (valid != patternContainerErrorShowing) {
-            patternContainerErrorShowing = valid;
-            pattern.setError(valid ? null : getString(R.string.filter_invalid_pattern));
-        }
+        pattern.setError(valid ? null : getString(R.string.filter_invalid_pattern));
 
         if (callback != null) {
             callback.setSaveButtonEnabled(valid);
@@ -385,7 +380,7 @@ private void updateFilterType() {
 
     private void updatePatternPreview() {
         String text = patternPreview.getText().toString();
-        boolean matches = text.length() > 0 && filterEngine.matches(filter, true, text, true);
+        boolean matches = filterEngine.matches(filter, true, text, true);
         patternPreviewStatus.setText(matches ? R.string.filter_matches : R.string.filter_no_matches);
     }