diff --git a/bochs/iodev/hdimage.cc b/bochs/iodev/hdimage.cc
index f3aa20d44..4d16bfdba 100644
--- a/bochs/iodev/hdimage.cc
+++ b/bochs/iodev/hdimage.cc
@@ -1006,6 +1006,7 @@ int redolog_t::make_header(const char* type, Bit64u size)
   Bit32u flip=0;
 
   // Set standard header values
+  memset(&header, 0, sizeof(redolog_header_t));
   strcpy((char*)header.standard.magic, STANDARD_HEADER_MAGIC);
   strcpy((char*)header.standard.type, REDOLOG_TYPE);
   strcpy((char*)header.standard.subtype, type);
diff --git a/bochs/iodev/sound/sb16.cc b/bochs/iodev/sound/sb16.cc
index b87e0dc00..846c1dea5 100644
--- a/bochs/iodev/sound/sb16.cc
+++ b/bochs/iodev/sound/sb16.cc
@@ -213,6 +213,8 @@ bx_sb16_c::bx_sb16_c(void)
   memset(&mpu401, 0, sizeof(mpu401));
   memset(&dsp, 0, sizeof(dsp));
   memset(&opl, 0, sizeof(opl));
+  currentdma8 = 0;
+  currentdma16 = 0;
   mpu401.timer_handle = BX_NULL_TIMER_HANDLE;
   dsp.timer_handle = BX_NULL_TIMER_HANDLE;
   opl.timer_handle = BX_NULL_TIMER_HANDLE;
diff --git a/bochs/iodev/vvfat.cc b/bochs/iodev/vvfat.cc
index d19d3488b..b6b96674a 100644
--- a/bochs/iodev/vvfat.cc
+++ b/bochs/iodev/vvfat.cc
@@ -113,6 +113,7 @@ static inline int array_ensure_allocated(array_t* array, int index)
     array->pointer = (char*)realloc(array->pointer, new_size);
     if (!array->pointer)
       return -1;
+    memset(array->pointer + array->size, 0, new_size - array->size);
     array->size = new_size;
     array->next = index + 1;
   }