diff --git a/base-nova/src/base/ipc/ipc.cc b/base-nova/src/base/ipc/ipc.cc
index 6c178ba8c..8f2f8f3cb 100644
--- a/base-nova/src/base/ipc/ipc.cc
+++ b/base-nova/src/base/ipc/ipc.cc
@@ -39,7 +39,7 @@ static void copy_utcb_to_msgbuf(Nova::Utcb *utcb, Msgbuf_base *rcv_msg)
 	/* look up and validate destination message buffer to receive the payload */
 	mword_t *msg_buf = (mword_t *)rcv_msg->buf;
 	if (num_msg_words*sizeof(mword_t) > rcv_msg->size()) {
-		PERR("receive message buffer too small msg size=%x, buf size=%zd",
+		PERR("receive message buffer too small msg size=%zx, buf size=%zd",
 		     num_msg_words*sizeof(mword_t), rcv_msg->size());
 		num_msg_words = rcv_msg->size()/sizeof(mword_t);
 	}
diff --git a/base-nova/src/core/core_rm_session.cc b/base-nova/src/core/core_rm_session.cc
index 1344b8a92..d1e2165f4 100644
--- a/base-nova/src/core/core_rm_session.cc
+++ b/base-nova/src/core/core_rm_session.cc
@@ -41,12 +41,12 @@ Core_rm_session::attach(Dataspace_capability ds_cap, size_t size,
 
 	if (use_local_addr) {
 		PERR("Parameter 'use_local_addr' not supported within core");
-		return 0;
+		return 0UL;
 	}
 
 	if (offset) {
 		PERR("Parameter 'offset' not supported within core");
-		return 0;
+		return 0UL;
 	}
 
 	/* allocate range in core's virtual address space */
diff --git a/base-nova/src/core/platform.cc b/base-nova/src/core/platform.cc
index 3276ad309..36ee5caaf 100644
--- a/base-nova/src/core/platform.cc
+++ b/base-nova/src/core/platform.cc
@@ -281,7 +281,8 @@ Platform::Platform() :
 	for (unsigned i = 0; i < num_mem_desc; i++, mem_desc++) {
 		if (mem_desc->type != Hip::Mem_desc::MULTIBOOT_MODULE) continue;
 
-		const char *name = commandline_to_basename((char *)mem_desc->aux);
+		addr_t aux = mem_desc->aux;
+		const char *name = commandline_to_basename(reinterpret_cast<char *>(aux));
 		printf("detected multi-boot module: %s 0x%lx-0x%lx\n", name,
 		       (long)mem_desc->addr, (long)(mem_desc->addr + mem_desc->size - 1));
 
diff --git a/base-nova/src/core/ram_session_support.cc b/base-nova/src/core/ram_session_support.cc
index 42c50e386..ce57ee3f3 100644
--- a/base-nova/src/core/ram_session_support.cc
+++ b/base-nova/src/core/ram_session_support.cc
@@ -63,7 +63,7 @@ void Ram_session_component::_clear_ds(Dataspace_component *ds)
 	}
 
 	if (verbose_ram_ds)
-		printf("-- ram ds size=%x phys %lx has core-local addr %p\n",
+		printf("-- ram ds size=%zx phys %lx has core-local addr %p\n",
 		       page_rounded_size, ds->phys_addr(), virt_addr);
 
 	/* map the dataspace's physical pages to local addresses */
diff --git a/os/src/test/ram_fs_chunk/main.cc b/os/src/test/ram_fs_chunk/main.cc
index 2e265e368..3d9ad3de1 100644
--- a/os/src/test/ram_fs_chunk/main.cc
+++ b/os/src/test/ram_fs_chunk/main.cc
@@ -101,10 +101,10 @@ int main(int, char **)
 	printf("--- ram_fs_chunk test ---\n");
 
 	PINF("chunk sizes");
-	PINF("  level 0: payload=%zd sizeof=%zd", Chunk_level_0::SIZE, sizeof(Chunk_level_0));
-	PINF("  level 1: payload=%zd sizeof=%zd", Chunk_level_1::SIZE, sizeof(Chunk_level_1));
-	PINF("  level 2: payload=%zd sizeof=%zd", Chunk_level_2::SIZE, sizeof(Chunk_level_2));
-	PINF("  level 3: payload=%zd sizeof=%zd", Chunk_level_3::SIZE, sizeof(Chunk_level_3));
+	PINF("  level 0: payload=%d sizeof=%zd", Chunk_level_0::SIZE, sizeof(Chunk_level_0));
+	PINF("  level 1: payload=%d sizeof=%zd", Chunk_level_1::SIZE, sizeof(Chunk_level_1));
+	PINF("  level 2: payload=%d sizeof=%zd", Chunk_level_2::SIZE, sizeof(Chunk_level_2));
+	PINF("  level 3: payload=%d sizeof=%zd", Chunk_level_3::SIZE, sizeof(Chunk_level_3));
 
 	static Allocator_tracer alloc(*env()->heap());