diff --git a/tinycap.c b/tinycap.c
index 7429750..c838348 100644
--- a/tinycap.c
+++ b/tinycap.c
@@ -191,6 +191,7 @@
     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 @@
     int size;
     int num_read;
 
+    memset(&config, 0, sizeof(config));
     config.channels = channels;
     config.rate = rate;
     config.period_size = period_size;