diff --git a/src/system_wrappers/source/trace_impl.cc b/src/system_wrappers/source/trace_impl.cc
index 6a9fbab2e2..c9be30ab9f 100644
--- a/src/system_wrappers/source/trace_impl.cc
+++ b/src/system_wrappers/source/trace_impl.cc
@@ -832,7 +832,8 @@ bool TraceImpl::UpdateFileName(
     }
 
     memcpy(fileNameWithCounterUTF8, fileNameUTF8, lengthTo_);
-    sprintf(fileNameWithCounterUTF8+lengthTo_, "_%lu%s", newCount,
+    sprintf(fileNameWithCounterUTF8+lengthTo_, "_%lu%s",
+            static_cast<long unsigned int> (newCount),
             fileNameUTF8+lengthWithoutFileEnding);
     return true;
 }
@@ -865,7 +866,8 @@ bool TraceImpl::CreateFileName(
     }
     memcpy(fileNameWithCounterUTF8, fileNameUTF8, lengthWithoutFileEnding);
     sprintf(fileNameWithCounterUTF8+lengthWithoutFileEnding, "_%lu%s",
-            newCount, fileNameUTF8+lengthWithoutFileEnding);
+            static_cast<long unsigned int> (newCount),
+            fileNameUTF8+lengthWithoutFileEnding);
     return true;
 }
 
diff --git a/src/system_wrappers/source/trace_posix.cc b/src/system_wrappers/source/trace_posix.cc
index 5fc60bf992..9bdd346f09 100644
--- a/src/system_wrappers/source/trace_posix.cc
+++ b/src/system_wrappers/source/trace_posix.cc
@@ -51,7 +51,8 @@ TracePosix::~TracePosix()
 WebRtc_Word32 TracePosix::AddThreadId(char* traceMessage) const
 {
     WebRtc_UWord64 threadId = (WebRtc_UWord64)pthread_self();
-    sprintf(traceMessage, "%10llu; ", threadId);
+    sprintf(traceMessage, "%10llu; ",
+            static_cast<long long unsigned int>(threadId));
     // 12 bytes are written.
     return 12;
 }