diff --git a/dom/base/ResponsiveImageSelector.cpp b/dom/base/ResponsiveImageSelector.cpp
index ea9c48f30d87..d4043aabe5c9 100644
--- a/dom/base/ResponsiveImageSelector.cpp
+++ b/dom/base/ResponsiveImageSelector.cpp
@@ -33,7 +33,6 @@ static bool ParseInteger(const nsAString& aString, int32_t& aInt) {
   return !(parseResult &
            (nsContentUtils::eParseHTMLInteger_Error |
             nsContentUtils::eParseHTMLInteger_DidNotConsumeAllInput |
-            nsContentUtils::eParseHTMLInteger_IsPercent |
             nsContentUtils::eParseHTMLInteger_NonStandard));
 }
 
diff --git a/dom/base/nsAttrValue.cpp b/dom/base/nsAttrValue.cpp
index e3d1cfbdf6cc..eafcf0fed337 100644
--- a/dom/base/nsAttrValue.cpp
+++ b/dom/base/nsAttrValue.cpp
@@ -1383,7 +1383,6 @@ bool nsAttrValue::ParseIntWithBounds(const nsAString& aString, int32_t aMin,
   val = std::min(val, aMax);
   bool nonStrict =
       (val != originalVal) ||
-      (result & nsContentUtils::eParseHTMLInteger_IsPercent) ||
       (result & nsContentUtils::eParseHTMLInteger_NonStandard) ||
       (result & nsContentUtils::eParseHTMLInteger_DidNotConsumeAllInput);
 
@@ -1409,8 +1408,7 @@ void nsAttrValue::ParseIntWithFallback(const nsAString& aString,
     nonStrict = true;
   }
 
-  if ((result & nsContentUtils::eParseHTMLInteger_IsPercent) ||
-      (result & nsContentUtils::eParseHTMLInteger_NonStandard) ||
+  if ((result & nsContentUtils::eParseHTMLInteger_NonStandard) ||
       (result & nsContentUtils::eParseHTMLInteger_DidNotConsumeAllInput)) {
     nonStrict = true;
   }
@@ -1426,7 +1424,6 @@ void nsAttrValue::ParseClampedNonNegativeInt(const nsAString& aString,
   nsContentUtils::ParseHTMLIntegerResultFlags result;
   int32_t val = nsContentUtils::ParseHTMLInteger(aString, &result);
   bool nonStrict =
-      (result & nsContentUtils::eParseHTMLInteger_IsPercent) ||
       (result & nsContentUtils::eParseHTMLInteger_NonStandard) ||
       (result & nsContentUtils::eParseHTMLInteger_DidNotConsumeAllInput);
 
@@ -1461,7 +1458,6 @@ bool nsAttrValue::ParseNonNegativeIntValue(const nsAString& aString) {
   }
 
   bool nonStrict =
-      (result & nsContentUtils::eParseHTMLInteger_IsPercent) ||
       (result & nsContentUtils::eParseHTMLInteger_NonStandard) ||
       (result & nsContentUtils::eParseHTMLInteger_DidNotConsumeAllInput);
 
@@ -1480,7 +1476,6 @@ bool nsAttrValue::ParsePositiveIntValue(const nsAString& aString) {
   }
 
   bool nonStrict =
-      (result & nsContentUtils::eParseHTMLInteger_IsPercent) ||
       (result & nsContentUtils::eParseHTMLInteger_NonStandard) ||
       (result & nsContentUtils::eParseHTMLInteger_DidNotConsumeAllInput);
 
diff --git a/dom/base/nsContentUtils.cpp b/dom/base/nsContentUtils.cpp
index 9b4a5af94529..a4e30fed4686 100644
--- a/dom/base/nsContentUtils.cpp
+++ b/dom/base/nsContentUtils.cpp
@@ -1182,10 +1182,6 @@ int32_t nsContentUtils::ParseHTMLInteger(const nsAString& aValue,
         break;
       }
       foundValue = true;
-    } else if (*iter == char16_t('%')) {
-      ++iter;
-      result |= eParseHTMLInteger_IsPercent;
-      break;
     } else {
       break;
     }
diff --git a/dom/base/nsContentUtils.h b/dom/base/nsContentUtils.h
index c31a539ab211..24580f129536 100644
--- a/dom/base/nsContentUtils.h
+++ b/dom/base/nsContentUtils.h
@@ -601,17 +601,16 @@ class nsContentUtils {
 
   enum ParseHTMLIntegerResultFlags {
     eParseHTMLInteger_NoFlags = 0,
-    eParseHTMLInteger_IsPercent = 1 << 0,
     // eParseHTMLInteger_NonStandard is set if the string representation of the
     // integer was not the canonical one (e.g. had extra leading '+' or '0').
-    eParseHTMLInteger_NonStandard = 1 << 1,
-    eParseHTMLInteger_DidNotConsumeAllInput = 1 << 2,
+    eParseHTMLInteger_NonStandard = 1 << 0,
+    eParseHTMLInteger_DidNotConsumeAllInput = 1 << 1,
     // Set if one or more error flags were set.
-    eParseHTMLInteger_Error = 1 << 3,
-    eParseHTMLInteger_ErrorNoValue = 1 << 4,
-    eParseHTMLInteger_ErrorOverflow = 1 << 5,
+    eParseHTMLInteger_Error = 1 << 2,
+    eParseHTMLInteger_ErrorNoValue = 1 << 3,
+    eParseHTMLInteger_ErrorOverflow = 1 << 4,
     // Use this flag to detect the difference between overflow and underflow
-    eParseHTMLInteger_Negative = 1 << 6,
+    eParseHTMLInteger_Negative = 1 << 5,
   };
   static int32_t ParseHTMLInteger(const nsAString& aValue,
                                   ParseHTMLIntegerResultFlags* aResult);