diff --git a/ext/serializer.c b/ext/serializer.c
index fad71b7998..c4f43661af 100644
--- a/ext/serializer.c
+++ b/ext/serializer.c
@@ -407,9 +407,7 @@ static void dd_add_post_fields_to_meta_recursive(zend_array *meta, const char *t
                 zend_string *postvalconcat = zend_strpprintf(0, "%s=%s", ZSTR_VAL(postkey), ZSTR_VAL(postvalstr));
                 zend_string_release(postvalstr);
 
-                // Match it with the regex to redact if needed and value is not an empty string
-                zend_string *regex_pattern = get_DD_TRACE_OBFUSCATION_QUERY_STRING_REGEXP();
-                if (strlen(regex_pattern) > 0 && zai_match_regex(regex_pattern, postvalconcat)) {
+                if (zai_match_regex(get_DD_TRACE_OBFUSCATION_QUERY_STRING_REGEXP(), postvalconcat)) {
                     zend_string *replacement = zend_string_init(ZEND_STRL("<redacted>"), 0);
                     dd_add_post_fields_to_meta(meta, type, postkey, replacement);
                     zend_string_release(replacement);
diff --git a/src/DDTrace/Util/Normalizer.php b/src/DDTrace/Util/Normalizer.php
index 2c3f67ec4a..042865a2fa 100644
--- a/src/DDTrace/Util/Normalizer.php
+++ b/src/DDTrace/Util/Normalizer.php
@@ -218,11 +218,13 @@ private static function generateFilteredPostFields($postKey, $postVal, array $wh
 
                 // Match it with the regex to redact if needed
                 $obfuscationRegex = \ini_get('datadog.trace.obfuscation_query_string_regexp');
-                $obfuscationRegex = '(' . $obfuscationRegex . ')';
-                if (preg_match($obfuscationRegex, $postField)) {
-                    return [$postKey => '<redacted>'];
-                } else {
-                    return [$postKey => $postVal];
+                if ($obfuscationRegex !== "") {
+                    $obfuscationRegex = '(' . $obfuscationRegex . ')';
+                    if (preg_match($obfuscationRegex, $postField)) {
+                        return [$postKey => '<redacted>'];
+                    } else {
+                        return [$postKey => $postVal];
+                    }
                 }
             } else {
                 // The postkey is not in the whitelist, and no wildcard set, then always use <redacted>
diff --git a/tests/Unit/Util/Normalizer/UriTest.php b/tests/Unit/Util/Normalizer/UriTest.php
index 2e0b427102..b1014043a7 100644
--- a/tests/Unit/Util/Normalizer/UriTest.php
+++ b/tests/Unit/Util/Normalizer/UriTest.php
@@ -13,6 +13,7 @@ protected function ddSetUp()
             'DD_TRACE_RESOURCE_URI_MAPPING_INCOMING',
             'DD_TRACE_RESOURCE_URI_MAPPING_OUTGOING',
             'DD_TRACE_RESOURCE_URI_QUERY_PARAM_ALLOWED',
+            'DD_TRACE_OBFUSCATION_QUERY_STRING_REGEXP',
         ]);
         parent::ddSetUp();
     }
@@ -25,6 +26,7 @@ protected function ddTearDown()
             'DD_TRACE_RESOURCE_URI_MAPPING_INCOMING',
             'DD_TRACE_RESOURCE_URI_MAPPING_OUTGOING',
             'DD_TRACE_RESOURCE_URI_QUERY_PARAM_ALLOWED',
+            'DD_TRACE_OBFUSCATION_QUERY_STRING_REGEXP',
         ]);
     }
 
@@ -486,6 +488,40 @@ public function testQueryParamPreserveWildcard()
         );
     }
 
+    public function testObfuscationQueryStringConfigured()
+    {
+        $this->putEnvAndReloadConfig([
+            'DD_TRACE_OBFUSCATION_QUERY_STRING_REGEXP=\d{3}-\d{2}-\d{4}',
+        ]);
+
+        $this->assertSame(
+            '/?<redacted>',
+            \DDTrace\Util\Normalizer::uriNormalizeIncomingPath('/?ssn=123-45-6789')
+        );
+        
+        $this->assertSame(
+            '/?<redacted>',
+            \DDTrace\Util\Normalizer::uriNormalizeOutgoingPath('/?ssn=123-45-6789')
+        );
+    }
+
+    public function testObfuscationQueryStringWithEmptyRegex()
+    {
+        $this->putEnvAndReloadConfig([
+            'DD_TRACE_OBFUSCATION_QUERY_STRING_REGEXP=""',
+        ]);
+    
+        $this->assertSame(
+            '/?application_key=123',
+            \DDTrace\Util\Normalizer::uriNormalizeIncomingPath('/?application_key=123')
+        );
+        
+        $this->assertSame(
+            '/?application_key=123',
+            \DDTrace\Util\Normalizer::uriNormalizeOutgoingPath('/?application_key=123')
+        );
+    }
+
     /**
      * @dataProvider dataProviderSanitizeNoDropUserinfo
      * @param string $url