Index: src/libcfa/concurrency/coroutine.c
===================================================================
--- src/libcfa/concurrency/coroutine.c	(revision 121ac138e6881955c99490249758e6b7918a1954)
+++ src/libcfa/concurrency/coroutine.c	(revision 25ba99989ac95d7ff7b36866920921f955fcf7c8)
@@ -156,5 +156,5 @@
 		this->limit = (char *)libCeiling( (unsigned long)this->storage, 16 ); // minimum alignment
 	} // if
-	assertf( this->size >= MinStackSize, "Stack size %d provides less than minimum of %d bytes for a stack.", this->size, MinStackSize );
+	assertf( this->size >= MinStackSize, "Stack size %zd provides less than minimum of %d bytes for a stack.", this->size, MinStackSize );
 
 	this->base = (char *)this->limit + this->size;
Index: src/libcfa/concurrency/monitor.c
===================================================================
--- src/libcfa/concurrency/monitor.c	(revision 121ac138e6881955c99490249758e6b7918a1954)
+++ src/libcfa/concurrency/monitor.c	(revision 25ba99989ac95d7ff7b36866920921f955fcf7c8)
@@ -17,4 +17,5 @@
 
 #include <stdlib>
+#include <inttypes.h>
 
 #include "libhdr.h"
@@ -378,6 +379,6 @@
 	// Check that everything is as expected
 	assertf( this.monitors != NULL, "Waiting with no monitors (%p)", this.monitors );
-	verifyf( this.monitor_count != 0, "Waiting with 0 monitors (%i)", this.monitor_count );
-	verifyf( this.monitor_count < 32u, "Excessive monitor count (%i)", this.monitor_count );
+	verifyf( this.monitor_count != 0, "Waiting with 0 monitors (%"PRIiFAST16")", this.monitor_count );
+	verifyf( this.monitor_count < 32u, "Excessive monitor count (%"PRIiFAST16")", this.monitor_count );
 
 	// Create storage for monitor context
@@ -462,5 +463,5 @@
 	//Check that everything is as expected
 	verifyf( this.monitors != NULL, "Waiting with no monitors (%p)", this.monitors );
-	verifyf( this.monitor_count != 0, "Waiting with 0 monitors (%i)", this.monitor_count );
+	verifyf( this.monitor_count != 0, "Waiting with 0 monitors (%"PRIiFAST16")", this.monitor_count );
 
 	// Create storage for monitor context