diff --git a/src/DDTrace/Util/Normalizer.php b/src/DDTrace/Util/Normalizer.php
index 042865a2fa..2c3f67ec4a 100644
--- a/src/DDTrace/Util/Normalizer.php
+++ b/src/DDTrace/Util/Normalizer.php
@@ -218,13 +218,11 @@ private static function generateFilteredPostFields($postKey, $postVal, array $wh
 
                 // Match it with the regex to redact if needed
                 $obfuscationRegex = \ini_get('datadog.trace.obfuscation_query_string_regexp');
-                if ($obfuscationRegex !== "") {
-                    $obfuscationRegex = '(' . $obfuscationRegex . ')';
-                    if (preg_match($obfuscationRegex, $postField)) {
-                        return [$postKey => '<redacted>'];
-                    } else {
-                        return [$postKey => $postVal];
-                    }
+                $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 b1014043a7..59e09358e3 100644
--- a/tests/Unit/Util/Normalizer/UriTest.php
+++ b/tests/Unit/Util/Normalizer/UriTest.php
@@ -13,7 +13,6 @@ 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();
     }
@@ -26,7 +25,6 @@ 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',
         ]);
     }
 
@@ -74,24 +72,6 @@ public function testWrongOutgoingConfigurationResultsInMissedPathNormalizationBu
         );
     }
 
-    public function testMixingFragmentRegexAndPatternMatchingIncoming()
-    {
-        $this->putEnvAndReloadConfig(['DD_TRACE_RESOURCE_URI_MAPPING_INCOMING=name/*']);
-        $this->assertSame(
-            '/numeric/?/name/?',
-            \DDTrace\Util\Normalizer::uriNormalizeIncomingPath('/numeric/123/name/some_name')
-        );
-    }
-
-    public function testMixingFragmentRegexAndPatternMatchingOutgoing()
-    {
-        $this->putEnvAndReloadConfig(['DD_TRACE_RESOURCE_URI_MAPPING_OUTGOING=name/*']);
-        $this->assertSame(
-            '/numeric/?/name/?',
-            \DDTrace\Util\Normalizer::uriNormalizeOutgoingPath('/numeric/123/name/some_name')
-        );
-    }
-
     /**
      * @dataProvider defaultPathNormalizationScenarios
      */
diff --git a/tests/ext/root_span_url_with_query_params_obfuscation_empty.phpt b/tests/ext/root_span_url_with_query_params_obfuscation_empty.phpt
new file mode 100644
index 0000000000..34ba57827a
--- /dev/null
+++ b/tests/ext/root_span_url_with_query_params_obfuscation_empty.phpt
@@ -0,0 +1,22 @@
+--TEST--
+Root span with http.url and unobfuscated query string with empty regex
+--ENV--
+DD_TRACE_GENERATE_ROOT_SPAN=0
+DD_TRACE_OBFUSCATION_QUERY_STRING_REGEXP=''
+HTTPS=off
+HTTP_HOST=localhost:9999
+SCRIPT_NAME=/foo.php
+REQUEST_URI=/users?application_key=123
+QUERY_STRING=application_key=123
+METHOD=GET
+--GET--
+application_key=123
+--FILE--
+<?php
+DDTrace\start_span();
+DDTrace\close_span();
+$spans = dd_trace_serialize_closed_spans();
+var_dump($spans[0]['meta']["http.url"]);
+?>
+--EXPECT--
+string(48) "https://localhost:9999/users?application_key=123"