diff --git a/hw/core/bus.c b/hw/core/bus.c
index 4651f24486..dceb144075 100644
--- a/hw/core/bus.c
+++ b/hw/core/bus.c
@@ -18,7 +18,7 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu-common.h"
+#include "qemu/cutils.h"
 #include "hw/qdev.h"
 #include "qapi/error.h"
 
diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
index 943dc2654b..3bdebac361 100644
--- a/hw/core/qdev-properties.c
+++ b/hw/core/qdev-properties.c
@@ -1,4 +1,5 @@
 #include "qemu/osdep.h"
+#include "qemu/cutils.h"
 #include "net/net.h"
 #include "hw/qdev.h"
 #include "qapi/error.h"
diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index fd9d0b0542..ed23bb7b3a 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -11,6 +11,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/cutils.h"
 #include "qapi/error.h"
 #include "cpu.h"
 #include "hw/boards.h"
diff --git a/hw/scsi/scsi-generic.c b/hw/scsi/scsi-generic.c
index 7237b4162e..86f65fd474 100644
--- a/hw/scsi/scsi-generic.c
+++ b/hw/scsi/scsi-generic.c
@@ -12,8 +12,8 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/cutils.h"
 #include "qapi/error.h"
-#include "qemu-common.h"
 #include "qemu/error-report.h"
 #include "hw/scsi/scsi.h"
 #include "hw/scsi/emulation.h"
diff --git a/include/qemu-common.h b/include/qemu-common.h
index 760527294f..ed43ae286d 100644
--- a/include/qemu-common.h
+++ b/include/qemu-common.h
@@ -33,22 +33,6 @@ int qemu_main(int argc, char **argv, char **envp);
 void qemu_get_timedate(struct tm *tm, int offset);
 int qemu_timedate_diff(struct tm *tm);
 
-#define qemu_isalnum(c)		isalnum((unsigned char)(c))
-#define qemu_isalpha(c)		isalpha((unsigned char)(c))
-#define qemu_iscntrl(c)		iscntrl((unsigned char)(c))
-#define qemu_isdigit(c)		isdigit((unsigned char)(c))
-#define qemu_isgraph(c)		isgraph((unsigned char)(c))
-#define qemu_islower(c)		islower((unsigned char)(c))
-#define qemu_isprint(c)		isprint((unsigned char)(c))
-#define qemu_ispunct(c)		ispunct((unsigned char)(c))
-#define qemu_isspace(c)		isspace((unsigned char)(c))
-#define qemu_isupper(c)		isupper((unsigned char)(c))
-#define qemu_isxdigit(c)	isxdigit((unsigned char)(c))
-#define qemu_tolower(c)		tolower((unsigned char)(c))
-#define qemu_toupper(c)		toupper((unsigned char)(c))
-#define qemu_isascii(c)		isascii((unsigned char)(c))
-#define qemu_toascii(c)		toascii((unsigned char)(c))
-
 void *qemu_oom_check(void *ptr);
 
 ssize_t qemu_write_full(int fd, const void *buf, size_t count)
diff --git a/include/qemu/cutils.h b/include/qemu/cutils.h
index 9ee40470e3..644f2d75bd 100644
--- a/include/qemu/cutils.h
+++ b/include/qemu/cutils.h
@@ -3,6 +3,31 @@
 
 #include "qemu/fprintf-fn.h"
 
+/**
+ * unsigned ctype macros:
+ *
+ * The standards require that the argument for these functions
+ * is either EOF or a value that is representable in the type
+ * unsigned char. If the argument is of type char, it must be
+ * cast to unsigned char. This is what these macros do,
+ * avoiding 'signed to unsigned' conversion warnings.
+ */
+#define qemu_isalnum(c)     isalnum((unsigned char)(c))
+#define qemu_isalpha(c)     isalpha((unsigned char)(c))
+#define qemu_iscntrl(c)     iscntrl((unsigned char)(c))
+#define qemu_isdigit(c)     isdigit((unsigned char)(c))
+#define qemu_isgraph(c)     isgraph((unsigned char)(c))
+#define qemu_islower(c)     islower((unsigned char)(c))
+#define qemu_isprint(c)     isprint((unsigned char)(c))
+#define qemu_ispunct(c)     ispunct((unsigned char)(c))
+#define qemu_isspace(c)     isspace((unsigned char)(c))
+#define qemu_isupper(c)     isupper((unsigned char)(c))
+#define qemu_isxdigit(c)    isxdigit((unsigned char)(c))
+#define qemu_tolower(c)     tolower((unsigned char)(c))
+#define qemu_toupper(c)     toupper((unsigned char)(c))
+#define qemu_isascii(c)     isascii((unsigned char)(c))
+#define qemu_toascii(c)     toascii((unsigned char)(c))
+
 /**
  * pstrcpy:
  * @buf: buffer to copy string into
diff --git a/qapi/qapi-util.c b/qapi/qapi-util.c
index e9b266bb70..ea93ae05d9 100644
--- a/qapi/qapi-util.c
+++ b/qapi/qapi-util.c
@@ -11,8 +11,8 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/cutils.h"
 #include "qapi/error.h"
-#include "qemu-common.h"
 
 const char *qapi_enum_lookup(const QEnumLookup *lookup, int val)
 {
diff --git a/qobject/json-parser.c b/qobject/json-parser.c
index 7a7ae9e8d1..06316f3a53 100644
--- a/qobject/json-parser.c
+++ b/qobject/json-parser.c
@@ -15,7 +15,6 @@
 #include "qemu/cutils.h"
 #include "qemu/unicode.h"
 #include "qapi/error.h"
-#include "qemu-common.h"
 #include "qapi/qmp/qbool.h"
 #include "qapi/qmp/qdict.h"
 #include "qapi/qmp/qlist.h"
diff --git a/target/ppc/monitor.c b/target/ppc/monitor.c
index 14915119fc..dbcb921231 100644
--- a/target/ppc/monitor.c
+++ b/target/ppc/monitor.c
@@ -22,6 +22,7 @@
  * THE SOFTWARE.
  */
 #include "qemu/osdep.h"
+#include "qemu/cutils.h"
 #include "cpu.h"
 #include "monitor/monitor.h"
 #include "monitor/hmp-target.h"
diff --git a/ui/keymaps.c b/ui/keymaps.c
index 085889b555..00b52a6db3 100644
--- a/ui/keymaps.c
+++ b/ui/keymaps.c
@@ -23,6 +23,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/cutils.h"
 #include "keymaps.h"
 #include "sysemu/sysemu.h"
 #include "trace.h"
diff --git a/util/id.c b/util/id.c
index 6141352955..ca21a77522 100644
--- a/util/id.c
+++ b/util/id.c
@@ -11,7 +11,7 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu-common.h"
+#include "qemu/cutils.h"
 #include "qemu/id.h"
 
 bool id_wellformed(const char *id)
diff --git a/util/readline.c b/util/readline.c
index ec91ee0fea..f3d8b0698a 100644
--- a/util/readline.c
+++ b/util/readline.c
@@ -23,7 +23,6 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu-common.h"
 #include "qemu/readline.h"
 #include "qemu/cutils.h"
 
