diff --git a/src/calls-log.c b/src/calls-log.c
index 46f49b8..687014d 100644
--- a/src/calls-log.c
+++ b/src/calls-log.c
@@ -20,7 +20,7 @@
 #define DEFAULT_DOMAIN_PREFIX "Calls"
 
 static char *domains;
-static int verbosity;
+static guint verbosity;
 static gboolean any_domain;
 static gboolean stderr_is_journal;
 
@@ -273,7 +273,7 @@ calls_log_increase_verbosity (void)
   verbosity++;
 }
 
-int
+guint
 calls_log_get_verbosity (void)
 {
   return verbosity;
diff --git a/src/calls-log.h b/src/calls-log.h
index cad93d2..fa3c3b2 100644
--- a/src/calls-log.h
+++ b/src/calls-log.h
@@ -11,6 +11,8 @@
 
 #pragma once
 
+#include <glib.h>
+
 #ifndef CALLS_LOG_LEVEL_TRACE
 # define CALLS_LOG_LEVEL_TRACE ((GLogLevelFlags)(1 << G_LOG_LEVEL_USER_SHIFT))
 # define CALLS_LOG_DETAILED ((GLogLevelFlags)(8 << G_LOG_LEVEL_USER_SHIFT))
@@ -34,6 +36,6 @@
                              __FILE__, G_STRINGIFY (__LINE__),          \
                              G_STRFUNC, __VA_ARGS__)
 
-void calls_log_init               (void);
-void calls_log_increase_verbosity (void);
-int  calls_log_get_verbosity      (void);
+void  calls_log_init               (void);
+void  calls_log_increase_verbosity (void);
+guint calls_log_get_verbosity      (void);