diff --git a/ipc/chromium/src/base/pickle.cc b/ipc/chromium/src/base/pickle.cc
index 0c1dd1a74787..3a1e7433414b 100644
--- a/ipc/chromium/src/base/pickle.cc
+++ b/ipc/chromium/src/base/pickle.cc
@@ -465,10 +465,10 @@ bool Pickle::WriteSentinel(uint32_t sentinel) {
 void Pickle::EndRead(PickleIterator& iter, uint32_t ipcMsgType) const {
   DCHECK(iter.iter_.Done());
 
-  if (ipcMsgType != 0) {
+  if (NS_IsMainThread() && ipcMsgType != 0) {
     uint32_t latencyMs = round((mozilla::TimeStamp::Now() - iter.start_).ToMilliseconds());
     if (latencyMs >= kMinTelemetryIPCReadLatencyMs) {
-      mozilla::Telemetry::Accumulate(mozilla::Telemetry::IPC_READ_LATENCY_MS,
+      mozilla::Telemetry::Accumulate(mozilla::Telemetry::IPC_READ_MAIN_THREAD_LATENCY_MS,
                                      nsDependentCString(mozilla::ipc::StringFromIPCMessageType(ipcMsgType)),
                                      latencyMs);
     }
diff --git a/ipc/glue/MessageChannel.cpp b/ipc/glue/MessageChannel.cpp
index 51efd5b47489..002a47b31e3f 100644
--- a/ipc/glue/MessageChannel.cpp
+++ b/ipc/glue/MessageChannel.cpp
@@ -786,12 +786,12 @@ MessageChannel::Send(Message* aMsg)
     }
 
     // If the message was created by the IPC bindings, the create time will be
-    // recorded. Use this information to report the IPC_WRITE_LATENCY_MS (time
+    // recorded. Use this information to report the IPC_WRITE_MAIN_THREAD_LATENCY_MS (time
     // from message creation to it being sent).
-    if (aMsg->create_time()) {
+    if (NS_IsMainThread() && aMsg->create_time()) {
         uint32_t latencyMs = round((mozilla::TimeStamp::Now() - aMsg->create_time()).ToMilliseconds());
         if (latencyMs >= kMinTelemetryIPCWriteLatencyMs) {
-            mozilla::Telemetry::Accumulate(mozilla::Telemetry::IPC_WRITE_LATENCY_MS,
+            mozilla::Telemetry::Accumulate(mozilla::Telemetry::IPC_WRITE_MAIN_THREAD_LATENCY_MS,
                                            nsDependentCString(aMsg->name()),
                                            latencyMs);
         }
diff --git a/toolkit/components/telemetry/Histograms.json b/toolkit/components/telemetry/Histograms.json
index 5a214f1014c1..1f61beb5a67e 100644
--- a/toolkit/components/telemetry/Histograms.json
+++ b/toolkit/components/telemetry/Histograms.json
@@ -11019,7 +11019,7 @@
     "description": "Results of displaying add-on installation notifications.",
     "releaseChannelCollection": "opt-out"
   },
-  "IPC_READ_LATENCY_MS": {
+  "IPC_READ_MAIN_THREAD_LATENCY_MS": {
     "alert_emails": ["mlayzell@mozilla.com"],
     "bug_numbers": [1342635],
     "expires_in_version": "60",
@@ -11027,9 +11027,9 @@
     "high": 500,
     "n_buckets": 20,
     "keyed": true,
-    "description": "Measures the number of milliseconds we spend waiting for IPC messages to deserialize their parameters. Note: only messages that take more than 500 microseconds are included in this probe. This probe is keyed on the IPDL message name."
+    "description": "Measures the number of milliseconds we spend waiting on the main thread for IPC messages to deserialize their parameters. Note: only messages that take more than 500 microseconds are included in this probe. This probe is keyed on the IPDL message name."
   },
-  "IPC_WRITE_LATENCY_MS": {
+  "IPC_WRITE_MAIN_THREAD_LATENCY_MS": {
     "alert_emails": ["mlayzell@mozilla.com"],
     "bug_numbers": [1342635],
     "expires_in_version": "60",
@@ -11037,6 +11037,6 @@
     "high": 500,
     "n_buckets": 20,
     "keyed": true,
-    "description": "Measures the number of milliseconds we spend waiting for IPC messages to serialize their parameters. Note: only messages that take more than 500 microseconds are included in this probe. This probe is keyed on the IPDL message name."
+    "description": "Measures the number of milliseconds we spend waiting on the main thread for IPC messages to serialize their parameters. Note: only messages that take more than 500 microseconds are included in this probe. This probe is keyed on the IPDL message name."
   }
 }