diff --git a/netwerk/protocol/http/HttpBaseChannel.cpp b/netwerk/protocol/http/HttpBaseChannel.cpp
index 61f65c2a14fb..288422a1b1e3 100644
--- a/netwerk/protocol/http/HttpBaseChannel.cpp
+++ b/netwerk/protocol/http/HttpBaseChannel.cpp
@@ -2032,20 +2032,6 @@ HttpBaseChannel::VisitOriginalResponseHeaders(nsIHttpHeaderVisitor* aVisitor) {
       aVisitor, nsHttpHeaderArray::eFilterResponseOriginal);
 }
 
-NS_IMETHODIMP
-HttpBaseChannel::GetAllowPipelining(bool* value) {
-  NS_ENSURE_ARG_POINTER(value);
-  *value = false;
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-HttpBaseChannel::SetAllowPipelining(bool value) {
-  ENSURE_CALLED_BEFORE_CONNECT();
-  // nop
-  return NS_OK;
-}
-
 NS_IMETHODIMP
 HttpBaseChannel::GetAllowSTS(bool* value) {
   NS_ENSURE_ARG_POINTER(value);
diff --git a/netwerk/protocol/http/HttpBaseChannel.h b/netwerk/protocol/http/HttpBaseChannel.h
index 09c273d469f8..427254d4e223 100644
--- a/netwerk/protocol/http/HttpBaseChannel.h
+++ b/netwerk/protocol/http/HttpBaseChannel.h
@@ -205,8 +205,6 @@ class HttpBaseChannel : public nsHashPropertyBag,
                                        nsIHttpHeaderVisitor* aVisitor) override;
   NS_IMETHOD VisitOriginalResponseHeaders(
       nsIHttpHeaderVisitor* aVisitor) override;
-  NS_IMETHOD GetAllowPipelining(bool* value) override;  // deprecated
-  NS_IMETHOD SetAllowPipelining(bool value) override;   // deprecated
   NS_IMETHOD GetAllowSTS(bool* value) override;
   NS_IMETHOD SetAllowSTS(bool value) override;
   NS_IMETHOD GetRedirectionLimit(uint32_t* value) override;
diff --git a/netwerk/protocol/http/NullHttpChannel.cpp b/netwerk/protocol/http/NullHttpChannel.cpp
index 983a272e5a1f..89d82ff55144 100644
--- a/netwerk/protocol/http/NullHttpChannel.cpp
+++ b/netwerk/protocol/http/NullHttpChannel.cpp
@@ -157,16 +157,6 @@ NullHttpChannel::VisitNonDefaultRequestHeaders(nsIHttpHeaderVisitor* aVisitor) {
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 
-NS_IMETHODIMP
-NullHttpChannel::GetAllowPipelining(bool* aAllowPipelining) {
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
-NS_IMETHODIMP
-NullHttpChannel::SetAllowPipelining(bool aAllowPipelining) {
-  return NS_ERROR_NOT_IMPLEMENTED;
-}
-
 NS_IMETHODIMP
 NullHttpChannel::GetAllowSTS(bool* aAllowSTS) {
   return NS_ERROR_NOT_IMPLEMENTED;
diff --git a/netwerk/protocol/http/nsIHttpChannel.idl b/netwerk/protocol/http/nsIHttpChannel.idl
index 0c61d079b879..774eb7592e17 100644
--- a/netwerk/protocol/http/nsIHttpChannel.idl
+++ b/netwerk/protocol/http/nsIHttpChannel.idl
@@ -206,13 +206,6 @@ interface nsIHttpChannel : nsIIdentChannel
      */
     [must_use] bool ShouldStripRequestBodyHeader(in ACString aMethod);
 
-    /**
-     * This attribute no longer has any effect, it remains for backwards compat
-     *
-     * @throws NS_ERROR_FAILURE if set after the channel has been opened.
-     */
-    [must_use] attribute boolean allowPipelining;
-
     /**
      * This attribute of the channel indicates whether or not
      * the underlying HTTP transaction should be honor stored Strict Transport
diff --git a/netwerk/protocol/viewsource/nsViewSourceChannel.cpp b/netwerk/protocol/viewsource/nsViewSourceChannel.cpp
index 45899a806ca5..8259753b2073 100644
--- a/netwerk/protocol/viewsource/nsViewSourceChannel.cpp
+++ b/netwerk/protocol/viewsource/nsViewSourceChannel.cpp
@@ -847,18 +847,6 @@ nsViewSourceChannel::ShouldStripRequestBodyHeader(const nsACString& aMethod,
              : mHttpChannel->ShouldStripRequestBodyHeader(aMethod, aResult);
 }
 
-NS_IMETHODIMP
-nsViewSourceChannel::GetAllowPipelining(bool* aAllowPipelining) {
-  return !mHttpChannel ? NS_ERROR_NULL_POINTER
-                       : mHttpChannel->GetAllowPipelining(aAllowPipelining);
-}
-
-NS_IMETHODIMP
-nsViewSourceChannel::SetAllowPipelining(bool aAllowPipelining) {
-  return !mHttpChannel ? NS_ERROR_NULL_POINTER
-                       : mHttpChannel->SetAllowPipelining(aAllowPipelining);
-}
-
 NS_IMETHODIMP
 nsViewSourceChannel::GetAllowSTS(bool* aAllowSTS) {
   return !mHttpChannel ? NS_ERROR_NULL_POINTER