diff --git a/tinycap.c b/tinycap.c
index be289d4..90b37cd 100644
--- a/tinycap.c
+++ b/tinycap.c
@@ -174,6 +174,7 @@ unsigned int capture_sample(FILE *file, unsigned int card, unsigned int device,
     unsigned int size;
     unsigned int bytes_read = 0;
 
+    memset(&config, 0, sizeof(config));
     config.channels = channels;
     config.rate = rate;
     config.period_size = period_size;
diff --git a/tinyplay.c b/tinyplay.c
index f4fac9f..88c54ae 100644
--- a/tinyplay.c
+++ b/tinyplay.c
@@ -218,6 +218,7 @@ void play_sample(FILE *file, unsigned int card, unsigned int device, unsigned in
     int size;
     int num_read;
 
+    memset(&config, 0, sizeof(config));
     config.channels = channels;
     config.rate = rate;
     config.period_size = period_size;