diff --git a/src/internal/pe_impl.h b/src/internal/pe_impl.h
index 313e1ac..c854824 100644
--- a/src/internal/pe_impl.h
+++ b/src/internal/pe_impl.h
@@ -19,7 +19,7 @@ struct pe_block {
 };
 
 
-static inline int32_t pe_impl_strlen_ansi(const char * str)
+static __inline__ int32_t pe_impl_strlen_ansi(const char * str)
 {
 	const char * ch;
 	const char * upper_bound;
@@ -35,7 +35,7 @@ static inline int32_t pe_impl_strlen_ansi(const char * str)
 }
 
 
-static inline int32_t pe_impl_strlen_utf16(const wchar16_t * str)
+static __inline__ int32_t pe_impl_strlen_utf16(const wchar16_t * str)
 {
 	const wchar16_t * wch;
 	const wchar16_t * upper_bound;
@@ -52,7 +52,7 @@ static inline int32_t pe_impl_strlen_utf16(const wchar16_t * str)
 }
 
 
-static inline wchar16_t pe_impl_utf16_char_to_lower(const wchar16_t c)
+static __inline__ wchar16_t pe_impl_utf16_char_to_lower(const wchar16_t c)
 {
 	return ((c >= 'A') && (c <= 'Z'))
 		? c + 'a' - 'A'