--- a/tools/profiler/GeckoProfilerImpl.h
+++ b/tools/profiler/GeckoProfilerImpl.h
@@ -70,19 +70,19 @@ void profiler_shutdown()
 {
 #ifdef MOZ_TASK_TRACER
   mozilla::tasktracer::ShutdownTaskTracer();
 #endif
   mozilla_sampler_shutdown();
 }
 
 static inline
-void profiler_start(int aProfileEntries, int aInterval,
-                       const char** aFeatures, uint32_t aFeatureCount,
-                       const char** aThreadNameFilters, uint32_t aFilterCount)
+void profiler_start(int aProfileEntries, double aInterval,
+                    const char** aFeatures, uint32_t aFeatureCount,
+                    const char** aThreadNameFilters, uint32_t aFilterCount)
 {
   mozilla_sampler_start(aProfileEntries, aInterval, aFeatures, aFeatureCount, aThreadNameFilters, aFilterCount);
 }
 
 static inline
 void profiler_stop()
 {
   mozilla_sampler_stop();