diff --git a/board/sg-cmd.c b/board/sg-cmd.c
index a375686..166422b 100644
--- a/board/sg-cmd.c
+++ b/board/sg-cmd.c
@@ -41,7 +41,7 @@ static HRESULT sg_req_validate(const void *ptr, size_t nbytes)
     if (req->hdr.frame_len != nbytes) {
         dprintf("SG Cmd: Frame length mismatch: got %i exp %i\n",
                 req->hdr.frame_len,
-                nbytes);
+                (int) nbytes);
 
         return E_FAIL;
     }
@@ -51,7 +51,7 @@ static HRESULT sg_req_validate(const void *ptr, size_t nbytes)
     if (req->payload_len != payload_len) {
         dprintf("SG Cmd: Payload length mismatch: got %i exp %i\n",
                 req->payload_len,
-                payload_len);
+                (int) payload_len);
 
         return E_FAIL;
     }
diff --git a/cardhook/_com12.c b/cardhook/_com12.c
index 78aefe1..2e32547 100644
--- a/cardhook/_com12.c
+++ b/cardhook/_com12.c
@@ -145,7 +145,7 @@ static HRESULT com12_mifare_poll(void *ctx, uint32_t *uid)
         r = fscanf(f, "%02x ", &byte);
 
         if (r != 1) {
-            dprintf("Aime reader: fscanf[%i] failed: %i\n", i, r);
+            dprintf("Aime reader: fscanf[%i] failed: %i\n", (int) i, r);
 
             goto end;
         }
diff --git a/nu/ds.c b/nu/ds.c
index d62dc6b..c7f3445 100644
--- a/nu/ds.c
+++ b/nu/ds.c
@@ -159,10 +159,10 @@ static HRESULT ds_handle_ioctl(struct irp *irp)
         return ds_ioctl_read_sector(irp);
 
     default:
-        dprintf("DS: Unknown ioctl %x, write %i read %i\n",
+        dprintf("DS: Unknown ioctl %08x, write %i read %i\n",
                 irp->ioctl,
-                irp->write.nbytes,
-                irp->read.nbytes);
+                (int) irp->write.nbytes,
+                (int) irp->read.nbytes);
 
         return HRESULT_FROM_WIN32(ERROR_INVALID_FUNCTION);
     }
diff --git a/nu/eeprom.c b/nu/eeprom.c
index 80971b1..807b2d4 100644
--- a/nu/eeprom.c
+++ b/nu/eeprom.c
@@ -100,8 +100,8 @@ static HRESULT eeprom_handle_ioctl(struct irp *irp)
     default:
         dprintf("EEPROM: Unknown ioctl %x, write %i read %i\n",
                 irp->ioctl,
-                irp->write.nbytes,
-                irp->read.nbytes);
+                (int) irp->write.nbytes,
+                (int) irp->read.nbytes);
 
         return HRESULT_FROM_WIN32(ERROR_INVALID_FUNCTION);
     }
@@ -143,7 +143,7 @@ static HRESULT eeprom_handle_read(struct irp *irp)
 
     dprintf("EEPROM: Read off %x len %x\n",
             (int) irp->ovl->Offset,
-            irp->read.nbytes);
+            (int) irp->read.nbytes);
 
     return iohook_invoke_next(irp);
 }
@@ -158,7 +158,7 @@ static HRESULT eeprom_handle_write(struct irp *irp)
 
     dprintf("EEPROM: Write off %x len %x\n",
             (int) irp->ovl->Offset,
-            irp->write.nbytes);
+            (int) irp->write.nbytes);
 
     return iohook_invoke_next(irp);
 }
diff --git a/nu/gpio.c b/nu/gpio.c
index be4960e..0eee74a 100644
--- a/nu/gpio.c
+++ b/nu/gpio.c
@@ -131,10 +131,10 @@ static HRESULT gpio_handle_ioctl(struct irp *irp)
         return gpio_ioctl_describe(irp);
 
     default:
-        dprintf("GPIO: IOCTL %08x write %i read %i\n",
+        dprintf("GPIO: Unknown ioctl %08x, write %i read %i\n",
                 irp->ioctl,
-                irp->write.nbytes,
-                irp->read.nbytes);
+                (int) irp->write.nbytes,
+                (int) irp->read.nbytes);
 
         return HRESULT_FROM_WIN32(ERROR_INVALID_FUNCTION);
     }
diff --git a/nu/hwmon.c b/nu/hwmon.c
index 2e34f1c..ded2d48 100644
--- a/nu/hwmon.c
+++ b/nu/hwmon.c
@@ -70,10 +70,10 @@ static HRESULT hwmon_handle_ioctl(struct irp *irp)
         return hwmon_ioctl_read_cpu_temp(irp);
 
     default:
-        dprintf("Hwmon: Unknown ioctl %08x write %i read %i\n",
+        dprintf("Hwmon: Unknown ioctl %08x, write %i read %i\n",
                 irp->ioctl,
-                irp->write.nbytes,
-                irp->read.nbytes);
+                (int) irp->write.nbytes,
+                (int) irp->read.nbytes);
 
         return HRESULT_FROM_WIN32(ERROR_INVALID_FUNCTION);
     }
diff --git a/nu/nusec.c b/nu/nusec.c
index 19ae177..c1ddf82 100644
--- a/nu/nusec.c
+++ b/nu/nusec.c
@@ -151,10 +151,10 @@ static HRESULT nusec_handle_ioctl(struct irp *irp)
         return nusec_ioctl_put_trace_log_data(irp);
 
     default:
-        dprintf("Security: Unhandled ioctl %#08x: read %i write %i\n",
+        dprintf("Security: Unknown ioctl %#08x, write %i read %i\n",
                 irp->ioctl,
-                irp->read.nbytes,
-                irp->write.nbytes);
+                (int) irp->write.nbytes,
+                (int) irp->read.nbytes);
 
         return HRESULT_FROM_WIN32(ERROR_INVALID_FUNCTION);
     }
@@ -241,9 +241,17 @@ static HRESULT nusec_ioctl_get_billing_ca_cert(struct irp *irp)
     irp->op = IRP_OP_READ;
     irp->fd = fd;
 
-    dprintf(">>> %p:%i/%i\n", irp->read.bytes, irp->read.pos, irp->read.nbytes);
+    dprintf(">>> %p:%i/%i\n",
+            irp->read.bytes,
+            (int) irp->read.pos,
+            (int) irp->read.nbytes);
+
     hr = iohook_invoke_next(irp);
-    dprintf("<<< %p:%i/%i\n", irp->read.bytes, irp->read.pos, irp->read.nbytes);
+
+    dprintf("<<< %p:%i/%i\n",
+            irp->read.bytes,
+            (int) irp->read.pos,
+            (int) irp->read.nbytes);
 
     if (FAILED(hr)) {
         dprintf("ReadFile transformation failed: %x\n", (int) hr);
@@ -280,9 +288,17 @@ static HRESULT nusec_ioctl_get_billing_pubkey(struct irp *irp)
     irp->op = IRP_OP_READ;
     irp->fd = fd;
 
-    dprintf(">>> %p:%i/%i\n", irp->read.bytes, irp->read.pos, irp->read.nbytes);
+    dprintf(">>> %p:%i/%i\n",
+            irp->read.bytes,
+            (int) irp->read.pos,
+            (int) irp->read.nbytes);
+
     hr = iohook_invoke_next(irp);
-    dprintf("<<< %p:%i/%i\n", irp->read.bytes, irp->read.pos, irp->read.nbytes);
+
+    dprintf("<<< %p:%i/%i\n",
+            irp->read.bytes,
+            (int) irp->read.pos,
+            (int) irp->read.nbytes);
 
     if (FAILED(hr)) {
         dprintf("ReadFile transformation failed: %x\n", (int) hr);
@@ -362,7 +378,7 @@ static HRESULT nusec_ioctl_get_trace_log_data(struct irp *irp)
         return hr;
     }
 
-    dprintf("    Params: %i %i Buf: %i\n", pos, count, irp->read.nbytes);
+    dprintf("    Params: %i %i Buf: %i\n", pos, count, (int) irp->read.nbytes);
 
     avail = irp->read.nbytes - irp->read.pos;
 
diff --git a/nu/sram.c b/nu/sram.c
index 9da5152..8424eac 100644
--- a/nu/sram.c
+++ b/nu/sram.c
@@ -96,8 +96,8 @@ static HRESULT sram_handle_ioctl(struct irp *irp)
     default:
         dprintf("SRAM: Unknown ioctl %x, write %i read %i\n",
                 irp->ioctl,
-                irp->write.nbytes,
-                irp->read.nbytes);
+                (int) irp->write.nbytes,
+                (int) irp->read.nbytes);
 
         return HRESULT_FROM_WIN32(ERROR_INVALID_FUNCTION);
     }
diff --git a/util/dump.c b/util/dump.c
index 6e85c89..79a3cb1 100644
--- a/util/dump.c
+++ b/util/dump.c
@@ -24,7 +24,7 @@ void dump(const void *ptr, size_t nbytes)
     bytes = ptr;
 
     for (i = 0 ; i < nbytes ; i += 16) {
-        dprintf("    %08x:", i);
+        dprintf("    %08x:", (int) i);
 
         for (j = 0 ; i + j < nbytes && j < 16 ; j++) {
             dprintf(" %02x", bytes[i + j]);