diff --git a/glib/gtestutils.c b/glib/gtestutils.c
index de70e921a..7730c77c9 100644
--- a/glib/gtestutils.c
+++ b/glib/gtestutils.c
@@ -19,8 +19,27 @@
  */
 
 #include "config.h"
+#include "gversionmacros.h"
+
+/**
+ * g_strcmp0:
+ * @str1: (nullable): a C string or %NULL
+ * @str2: (nullable): another C string or %NULL
+ *
+ * Compares @str1 and @str2 like strcmp(). Handles %NULL
+ * gracefully by sorting it before non-%NULL strings.
+ * Comparing two %NULL pointers returns 0.
+ *
+ * Returns: an integer less than, equal to, or greater than zero, if @str1 is <, == or > than @str2.
+ *
+ * Since: 2.16
+ */
+
+GLIB_AVAILABLE_IN_ALL
+int g_strcmp0 (const char *str1, const char *str2);
 
 #include "gtestutils.h"
+
 #include "gfileutils.h"
 
 #include <sys/types.h>
@@ -3397,30 +3416,6 @@ g_assertion_message_error (const char     *domain,
   g_string_free (gstring, TRUE);
 }
 
-/**
- * g_strcmp0:
- * @str1: (nullable): a C string or %NULL
- * @str2: (nullable): another C string or %NULL
- *
- * Compares @str1 and @str2 like strcmp(). Handles %NULL
- * gracefully by sorting it before non-%NULL strings.
- * Comparing two %NULL pointers returns 0.
- *
- * Returns: an integer less than, equal to, or greater than zero, if @str1 is <, == or > than @str2.
- *
- * Since: 2.16
- */
-int
-g_strcmp0 (const char     *str1,
-           const char     *str2)
-{
-  if (!str1)
-    return -(str1 != str2);
-  if (!str2)
-    return str1 != str2;
-  return strcmp (str1, str2);
-}
-
 static void
 test_trap_clear (void)
 {
diff --git a/glib/gtestutils.h b/glib/gtestutils.h
index 4e38eb414..969c69dda 100644
--- a/glib/gtestutils.h
+++ b/glib/gtestutils.h
@@ -238,9 +238,20 @@ typedef void (*GTestFixtureFunc) (gpointer      fixture,
                                         } G_STMT_END
 #endif /* !G_DISABLE_ASSERT */
 
-GLIB_AVAILABLE_IN_ALL
-int     g_strcmp0                       (const char     *str1,
-                                         const char     *str2);
+#ifndef GLIB_INLINE
+#define GLIB_INLINE
+#endif
+
+GLIB_INLINE int
+g_strcmp0 (const char *str1,
+           const char *str2)
+{
+  if (!str1)
+    return -(str1 != str2);
+  if (!str2)
+    return str1 != str2;
+  return strcmp (str1, str2);
+}
 
 /* report performance results */
 GLIB_AVAILABLE_IN_ALL