diff --git a/src/main/java/bubble/abp/BlockTarget.java b/src/main/java/bubble/abp/BlockTarget.java
index b1b8fb5..1ef506a 100644
--- a/src/main/java/bubble/abp/BlockTarget.java
+++ b/src/main/java/bubble/abp/BlockTarget.java
@@ -37,6 +37,14 @@ public class BlockTarget {
     public boolean hasRegex() { return !empty(regex); }
     @JsonIgnore @Getter(lazy=true) private final Pattern regexPattern = hasRegex() ? Pattern.compile(getRegex()) : null;
 
+    @SuppressWarnings("ResultOfMethodCallIgnored")
+    public BlockTarget validatePatterns() {
+        // force lazy-init patterns to initialize, validates regex patterns
+        if (hasRegex()) getRegexPattern();
+        if (hasDomainRegex()) getDomainPattern();
+        return this;
+    }
+
     @Getter @Setter private BubbleBlockCondition[] conditions;
     public boolean hasConditions () { return !empty(conditions); }
 
@@ -144,7 +152,8 @@ public class BlockTarget {
         return new BlockTarget()
                 .setDomainRegex(domainRegex)
                 .setRegex(regex)
-                .setFullDomainBlock(regex == null ? fullBlock : null);
+                .setFullDomainBlock(regex == null ? fullBlock : null)
+                .validatePatterns();
     }
 
     private static String parseWildcardMatch(String data) {
diff --git a/src/main/java/bubble/abp/BubbleBlockConditionOperation.java b/src/main/java/bubble/abp/BubbleBlockConditionOperation.java
index bc34c1e..5ecb225 100644
--- a/src/main/java/bubble/abp/BubbleBlockConditionOperation.java
+++ b/src/main/java/bubble/abp/BubbleBlockConditionOperation.java
@@ -5,11 +5,10 @@ import lombok.AllArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.cobbzilla.util.collection.ExpirationEvictionPolicy;
 import org.cobbzilla.util.collection.ExpirationMap;
+import org.cobbzilla.util.string.ValidationRegexes;
 
 import java.util.regex.Pattern;
 
-import static java.util.regex.Pattern.CASE_INSENSITIVE;
-
 @AllArgsConstructor @Slf4j
 public enum BubbleBlockConditionOperation {
 
@@ -20,8 +19,9 @@ public enum BubbleBlockConditionOperation {
     contains ((input, value) -> value.contains(input));
 
     private static final ExpirationMap<String, Pattern> PATTERN_CACHE = new ExpirationMap<>(ExpirationEvictionPolicy.atime);
+
     private static Pattern pattern(String value) {
-        return PATTERN_CACHE.computeIfAbsent(value, k -> Pattern.compile(k, CASE_INSENSITIVE));
+        return PATTERN_CACHE.computeIfAbsent(value, ValidationRegexes::safePattern);
     }
 
     private interface BubbleBlockConditionComparison { boolean matches(String input, String value); }