diff --git a/cfg.mk b/cfg.mk
index 8c9bab5..3713860 100644
--- a/cfg.mk
+++ b/cfg.mk
@@ -74,4 +74,4 @@ exclude_file_name_regexp--sc_space_tab = ^gl/lib/.*\.c\.diff$$
 exclude_file_name_regexp--sc_prohibit_doubled_word = ^tests/y2038-vs-32bit$$
 
 # Tell gnulib's tight_scope rule that we mark externs with XTERN
-export _gl_TS_extern = extern|XTERN|DIFF_INLINE
+export _gl_TS_extern = extern|XTERN|DIFF_INLINE|SYSTEM_INLINE
diff --git a/src/system.h b/src/system.h
index ce4758d..f82ae61 100644
--- a/src/system.h
+++ b/src/system.h
@@ -212,8 +212,7 @@ verify (LIN_MAX <= IDX_MAX);
 #define STREQ(a, b) (strcmp (a, b) == 0)
 
 /* Return the floor of the log base 2 of N.  Return -1 if N is zero.  */
-SYSTEM_INLINE int
-floor_log2 (idx_t n)
+SYSTEM_INLINE int floor_log2 (idx_t n)
 {
   verify (IDX_MAX <= ULLONG_MAX);
   return ULLONG_WIDTH - 1 - count_leading_zeros_ll (n);