diff --git a/mozglue/baseprofiler/public/BaseProfileJSONWriter.h b/mozglue/baseprofiler/public/BaseProfileJSONWriter.h
index 511dc00734f7..596162d75b24 100644
--- a/mozglue/baseprofiler/public/BaseProfileJSONWriter.h
+++ b/mozglue/baseprofiler/public/BaseProfileJSONWriter.h
@@ -164,7 +164,7 @@ class UniqueJSONStrings;
 class SpliceableJSONWriter : public JSONWriter {
  public:
   explicit SpliceableJSONWriter(UniquePtr<JSONWriteFunc> aWriter)
-      : JSONWriter(std::move(aWriter)) {}
+      : JSONWriter(std::move(aWriter), JSONWriter::SingleLineStyle) {}
 
   void StartBareList(CollectionStyle aStyle = MultiLineStyle) {
     StartCollection(scEmptyString, scEmptyString, aStyle);
@@ -325,7 +325,7 @@ class SpliceableJSONWriter : public JSONWriter {
 
 class SpliceableChunkedJSONWriter final : public SpliceableJSONWriter {
  public:
-  explicit SpliceableChunkedJSONWriter()
+  SpliceableChunkedJSONWriter()
       : SpliceableJSONWriter(MakeUnique<ChunkedJSONWriteFunc>()) {}
 
   // Access the ChunkedJSONWriteFunc as reference-to-const, usually to copy data
diff --git a/mozglue/tests/TestBaseProfiler.cpp b/mozglue/tests/TestBaseProfiler.cpp
index a9b9c2393414..0c172b1ca0c5 100644
--- a/mozglue/tests/TestBaseProfiler.cpp
+++ b/mozglue/tests/TestBaseProfiler.cpp
@@ -1170,14 +1170,14 @@ void CheckJSON(mozilla::baseprofiler::SpliceableJSONWriter& aWriter,
 void TestJSONTimeOutput() {
   printf("TestJSONTimeOutput...\n");
 
-#  define TEST(in, out)                                        \
-    do {                                                       \
-      mozilla::baseprofiler::SpliceableJSONWriter writer(      \
-          mozilla::MakeUnique<StringWriteFunc>());             \
-      writer.Start(mozilla::JSONWriter::SingleLineStyle);      \
-      writer.TimeDoubleMsProperty("time_ms", (in));            \
-      writer.End();                                            \
-      CheckJSON(writer, "{\"time_ms\": " out "}\n", __LINE__); \
+#  define TEST(in, out)                                      \
+    do {                                                     \
+      mozilla::baseprofiler::SpliceableJSONWriter writer(    \
+          mozilla::MakeUnique<StringWriteFunc>());           \
+      writer.Start(mozilla::JSONWriter::SingleLineStyle);    \
+      writer.TimeDoubleMsProperty("time_ms", (in));          \
+      writer.End();                                          \
+      CheckJSON(writer, "{\"time_ms\": " out "}", __LINE__); \
     } while (false);
 
   TEST(0, "0");
@@ -4861,7 +4861,7 @@ static void VerifyUniqueStringContents(
   expected += aExpectedData;
   expected += "], \"stringTable\": [";
   expected += aExpectedUniqueStrings;
-  expected += "]}\n";
+  expected += "]}";
   if (jsonStringView != expected) {
     fprintf(stderr,
             "Expected:\n"
diff --git a/tools/profiler/tests/gtest/GeckoProfiler.cpp b/tools/profiler/tests/gtest/GeckoProfiler.cpp
index 1cd9cb8b8b4b..0187cf4acb9d 100644
--- a/tools/profiler/tests/gtest/GeckoProfiler.cpp
+++ b/tools/profiler/tests/gtest/GeckoProfiler.cpp
@@ -1288,7 +1288,7 @@ void JSONWhitespaceCheck(const char* aOutput) {
     }
   }
 
-  EXPECT_LE(double(whitespaces) / double(length), 0.25);
+  EXPECT_LE(double(whitespaces) / double(length), 0.125);
 }
 
 // Does the GETTER return a non-null TYPE? (Non-critical)