diff --git a/sparsnas_decode.cpp b/sparsnas_decode.cpp
index c222831..c5a705f 100644
--- a/sparsnas_decode.cpp
+++ b/sparsnas_decode.cpp
@@ -213,7 +213,7 @@ class SignalDetector {
   uint32_t bits_;
 };
 
-int run_for_frequencies(FILE *f, FILE *logfile, float F1, float F2) {
+void run_for_frequencies(FILE *f, FILE *logfile, float F1, float F2) {
   uint8_t buf[16384];
   SignalDetector sd;