diff --git a/src/basic/os-util.c b/src/basic/os-util.c
index 8cb8d9302b..5f1c26b87c 100644
--- a/src/basic/os-util.c
+++ b/src/basic/os-util.c
@@ -14,11 +14,21 @@
 #include "parse-util.h"
 #include "path-util.h"
 #include "stat-util.h"
+#include "string-table.h"
 #include "string-util.h"
 #include "strv.h"
 #include "utf8.h"
 #include "xattr-util.h"
 
+static const char* const image_class_table[_IMAGE_CLASS_MAX] = {
+        [IMAGE_MACHINE]  = "machine",
+        [IMAGE_PORTABLE] = "portable",
+        [IMAGE_SYSEXT]   = "extension",
+        [IMAGE_CONFEXT]  = "confext",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(image_class, ImageClass);
+
 /* Helper struct for naming simplicity and reusability */
 static const struct {
         const char *release_file_directory;
@@ -55,8 +65,6 @@ int path_is_extension_tree(ImageClass image_class, const char *path, const char
         int r;
 
         assert(path);
-        assert(image_class >= 0);
-        assert(image_class < _IMAGE_CLASS_MAX);
 
         /* Does the path exist at all? If not, generate an error immediately. This is useful so that a missing root dir
          * always results in -ENOENT, and we can properly distinguish the case where the whole root doesn't exist from
@@ -295,24 +303,12 @@ int _parse_os_release(const char *root, ...) {
         int r;
 
         va_start(ap, root);
-        r = parse_release_internal(root, -1, /* relax_extension_release_check= */ false, NULL, ap);
+        r = parse_release_internal(root, _IMAGE_CLASS_INVALID, /* relax_extension_release_check= */ false, NULL, ap);
         va_end(ap);
 
         return r;
 }
 
-int load_os_release_pairs(const char *root, char ***ret) {
-        _cleanup_fclose_ FILE *f = NULL;
-        _cleanup_free_ char *p = NULL;
-        int r;
-
-        r = fopen_os_release(root, &p, &f);
-        if (r < 0)
-                return r;
-
-        return load_env_file_pairs(f, p, ret);
-}
-
 int load_os_release_pairs_with_prefix(const char *root, const char *prefix, char ***ret) {
         _cleanup_strv_free_ char **os_release_pairs = NULL, **os_release_pairs_prefixed = NULL;
         int r;
@@ -347,9 +343,6 @@ int load_extension_release_pairs(const char *root, ImageClass image_class, const
         _cleanup_free_ char *p = NULL;
         int r;
 
-        assert(image_class >= 0);
-        assert(image_class < _IMAGE_CLASS_MAX);
-
         r = fopen_extension_release(root, image_class, extension, relax_extension_release_check, &p, &f);
         if (r < 0)
                 return r;
diff --git a/src/basic/os-util.h b/src/basic/os-util.h
index 2f641ba9cd..01dcde7a80 100644
--- a/src/basic/os-util.h
+++ b/src/basic/os-util.h
@@ -5,6 +5,7 @@
 #include <stdio.h>
 
 #include "time-util.h"
+
 typedef enum ImageClass {
         IMAGE_MACHINE,
         IMAGE_PORTABLE,
@@ -24,17 +25,17 @@ bool image_name_is_valid(const char *s) _pure_;
 
 int path_is_extension_tree(ImageClass image_class, const char *path, const char *extension, bool relax_extension_release_check);
 static inline int path_is_os_tree(const char *path) {
-        return path_is_extension_tree(IMAGE_SYSEXT, path, NULL, false);
+        return path_is_extension_tree(_IMAGE_CLASS_INVALID, path, NULL, false);
 }
 
 int open_extension_release(const char *root, ImageClass image_class, const char *extension, bool relax_extension_release_check, char **ret_path, int *ret_fd);
 static inline int open_os_release(const char *root, char **ret_path, int *ret_fd) {
-        return open_extension_release(root, IMAGE_SYSEXT, NULL, false, ret_path, ret_fd);
+        return open_extension_release(root, _IMAGE_CLASS_INVALID, NULL, false, ret_path, ret_fd);
 }
 
 int fopen_extension_release(const char *root, ImageClass image_class, const char *extension, bool relax_extension_release_check, char **ret_path, FILE **ret_file);
 static inline int fopen_os_release(const char *root, char **ret_path, FILE **ret_file) {
-        return fopen_extension_release(root, IMAGE_SYSEXT, NULL, false, ret_path, ret_file);
+        return fopen_extension_release(root, _IMAGE_CLASS_INVALID, NULL, false, ret_path, ret_file);
 }
 
 int _parse_extension_release(const char *root, ImageClass image_class, bool relax_extension_release_check, const char *extension, ...) _sentinel_;
@@ -43,7 +44,9 @@ int _parse_os_release(const char *root, ...) _sentinel_;
 #define parse_os_release(root, ...) _parse_os_release(root, __VA_ARGS__, NULL)
 
 int load_extension_release_pairs(const char *root, ImageClass image_class, const char *extension, bool relax_extension_release_check, char ***ret);
-int load_os_release_pairs(const char *root, char ***ret);
+static inline int load_os_release_pairs(const char *root, char ***ret) {
+        return load_extension_release_pairs(root, _IMAGE_CLASS_INVALID, NULL, false, ret);
+}
 int load_os_release_pairs_with_prefix(const char *root, const char *prefix, char ***ret);
 
 int os_release_support_ended(const char *support_end, bool quiet, usec_t *ret_eol);
diff --git a/src/shared/discover-image.c b/src/shared/discover-image.c
index 0343d2e20b..d0b3245a27 100644
--- a/src/shared/discover-image.c
+++ b/src/shared/discover-image.c
@@ -1326,12 +1326,3 @@ static const char* const image_type_table[_IMAGE_TYPE_MAX] = {
 };
 
 DEFINE_STRING_TABLE_LOOKUP(image_type, ImageType);
-
-static const char* const image_class_table[_IMAGE_CLASS_MAX] = {
-        [IMAGE_MACHINE] = "machine",
-        [IMAGE_PORTABLE] = "portable",
-        [IMAGE_SYSEXT] = "extension",
-        [IMAGE_CONFEXT] = "confext"
-};
-
-DEFINE_STRING_TABLE_LOOKUP(image_class, ImageClass);