diff --git a/Changelog.txt b/Changelog.txt
index cd1b4c3ef..461058279 100644
--- a/Changelog.txt
+++ b/Changelog.txt
@@ -17,6 +17,7 @@ common:
 	* Fixed issue #23. Fixed a bug of f_check script about generating link flags.
 	* Added openblas_set_num_threads for Fortran.
 	* Fixed #25 a wrong result of rotmg.
+	* Fixed a bug about detecting underscore prefix in c_check.
 
 x86/x86_64:
 	* Fixed #28 a wrong result of dsdot on x86_64.
diff --git a/c_check b/c_check
index d8025f9f3..263efeb3d 100644
--- a/c_check
+++ b/c_check
@@ -149,7 +149,7 @@ $binformat    = bin64  if ($data =~ /BINARY_64/);
 
 $data = `$compiler_name -S ctest1.c && grep globl ctest1.s | head -n 1 && rm -f ctest1.s`;
 
-$data =~ /globl\ ([_\.]*)(.*)/;
+$data =~ /globl\s([_\.]*)(.*)/;
 
 $need_fu      = $1;