diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3486190..b3e3116 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -131,7 +131,7 @@ ELSE()
 	MESSAGE(FATAL_ERROR "invalid cryptographic support requested: ${CRYPT}")
 ENDIF()
 
-SET(CMAKE_C_FLAGS "-std=gnu99 -D_DEFAULT_SOURCE")
+SET(CMAKE_C_FLAGS "-D_DEFAULT_SOURCE")
 
 ENABLE_WARNINGS(all)
 ENABLE_WARNINGS(extra)
@@ -179,6 +179,8 @@ IF(BUILD_LIBRARY)
 	SET_PROPERTY(TARGET ntlmclient PROPERTY POSITION_INDEPENDENT_CODE 1)
 
 	ADD_LIBRARY(ntlmclient_shared SHARED $<TARGET_OBJECTS:ntlmclient>)
+	SET_TARGET_PROPERTIES(ntlmclient_shared PROPERTIES C_STANDARD 90)
+	SET_TARGET_PROPERTIES(ntlmclient_shared PROPERTIES C_EXTENSIONS OFF)
 	SET_TARGET_PROPERTIES(ntlmclient_shared PROPERTIES OUTPUT_NAME ntlmclient)
 	SET_TARGET_PROPERTIES(ntlmclient_shared PROPERTIES VERSION ${NTLM_VERSION})
 	SET_TARGET_PROPERTIES(ntlmclient_shared PROPERTIES SOVERSION ${NTLM_SOVERSION})
diff --git a/src/crypt_openssl.c b/src/crypt_openssl.c
index c4be129..7d757f6 100644
--- a/src/crypt_openssl.c
+++ b/src/crypt_openssl.c
@@ -26,18 +26,18 @@
 
 #if OPENSSL_VERSION_NUMBER < 0x10100000L || defined(CRYPT_OPENSSL_DYNAMIC)
 
-static inline HMAC_CTX *HMAC_CTX_new(void)
+NTLM_INLINE(HMAC_CTX *) HMAC_CTX_new(void)
 {
 	return calloc(1, sizeof(HMAC_CTX));
 }
 
-static inline int HMAC_CTX_reset(HMAC_CTX *ctx)
+NTLM_INLINE(int) HMAC_CTX_reset(HMAC_CTX *ctx)
 {
 	ntlm_memzero(ctx, sizeof(HMAC_CTX));
 	return 1;
 }
 
-static inline void HMAC_CTX_free(HMAC_CTX *ctx)
+NTLM_INLINE(void) HMAC_CTX_free(HMAC_CTX *ctx)
 {
 	free(ctx);
 }
diff --git a/src/ntlm.c b/src/ntlm.c
index ad4de5d..44421f5 100644
--- a/src/ntlm.c
+++ b/src/ntlm.c
@@ -43,7 +43,7 @@ static bool supports_unicode(ntlm_client *ntlm)
 		false : true;
 }
 
-static inline bool increment_size(size_t *out, size_t incr)
+NTLM_INLINE(bool) increment_size(size_t *out, size_t incr)
 {
 	if (SIZE_MAX - *out < incr) {
 		*out = (size_t)-1;
@@ -272,7 +272,7 @@ int ntlm_client_set_timestamp(ntlm_client *ntlm, uint64_t timestamp)
 	return 0;
 }
 
-static inline bool write_buf(
+NTLM_INLINE(bool) write_buf(
 	ntlm_client *ntlm,
 	ntlm_buf *out,
 	const unsigned char *buf,
@@ -291,7 +291,7 @@ static inline bool write_buf(
 	return true;
 }
 
-static inline bool write_byte(
+NTLM_INLINE(bool) write_byte(
 	ntlm_client *ntlm,
 	ntlm_buf *out,
 	uint8_t value)
@@ -305,7 +305,7 @@ static inline bool write_byte(
 	return true;
 }
 
-static inline bool write_int16(
+NTLM_INLINE(bool) write_int16(
 	ntlm_client *ntlm,
 	ntlm_buf *out,
 	uint16_t value)
@@ -320,7 +320,7 @@ static inline bool write_int16(
 	return true;
 }
 
-static inline bool write_int32(
+NTLM_INLINE(bool) write_int32(
 	ntlm_client *ntlm,
 	ntlm_buf *out,
 	uint32_t value)
@@ -337,7 +337,7 @@ static inline bool write_int32(
 	return true;
 }
 
-static inline bool write_version(
+NTLM_INLINE(bool) write_version(
 	ntlm_client *ntlm,
 	ntlm_buf *out,
 	ntlm_version *version)
@@ -348,7 +348,7 @@ static inline bool write_version(
 		write_int32(ntlm, out, version->reserved);
 }
 
-static inline bool write_bufinfo(
+NTLM_INLINE(bool) write_bufinfo(
 	ntlm_client *ntlm,
 	ntlm_buf *out,
 	size_t len,
@@ -369,7 +369,7 @@ static inline bool write_bufinfo(
 		write_int32(ntlm, out, (uint32_t)offset);
 }
 
-static inline bool read_buf(
+NTLM_INLINE(bool) read_buf(
 	unsigned char *out,
 	ntlm_client *ntlm,
 	ntlm_buf *message,
@@ -386,7 +386,7 @@ static inline bool read_buf(
 	return true;
 }
 
-static inline bool read_byte(
+NTLM_INLINE(bool) read_byte(
 	uint8_t *out,
 	ntlm_client *ntlm,
 	ntlm_buf *message)
@@ -400,7 +400,7 @@ static inline bool read_byte(
 	return true;
 }
 
-static inline bool read_int16(
+NTLM_INLINE(bool) read_int16(
 	uint16_t *out,
 	ntlm_client *ntlm,
 	ntlm_buf *message)
@@ -418,7 +418,7 @@ static inline bool read_int16(
 	return true;
 }
 
-static inline bool read_int32(
+NTLM_INLINE(bool) read_int32(
 	uint32_t *out,
 	ntlm_client *ntlm,
 	ntlm_buf *message)
@@ -438,7 +438,7 @@ static inline bool read_int32(
 	return true;
 }
 
-static inline bool read_int64(
+NTLM_INLINE(bool) read_int64(
 	uint64_t *out,
 	ntlm_client *ntlm,
 	ntlm_buf *message)
@@ -462,7 +462,7 @@ static inline bool read_int64(
 	return true;
 }
 
-static inline bool read_version(
+NTLM_INLINE(bool) read_version(
 	ntlm_version *out,
 	ntlm_client *ntlm,
 	ntlm_buf *message)
@@ -473,7 +473,7 @@ static inline bool read_version(
 		read_int32(&out->reserved, ntlm, message);
 }
 
-static inline bool read_bufinfo(
+NTLM_INLINE(bool) read_bufinfo(
 	uint16_t *out_len,
 	uint32_t *out_offset,
 	ntlm_client *ntlm,
@@ -486,7 +486,7 @@ static inline bool read_bufinfo(
 		read_int32(out_offset, ntlm, message);
 }
 
-static inline bool read_string_unicode(
+NTLM_INLINE(bool) read_string_unicode(
 	char **out,
 	ntlm_client *ntlm,
 	ntlm_buf *message,
@@ -504,7 +504,7 @@ static inline bool read_string_unicode(
 	return ret;
 }
 
-static inline bool read_string_ascii(
+NTLM_INLINE(bool) read_string_ascii(
 	char **out,
 	ntlm_client *ntlm,
 	ntlm_buf *message,
@@ -526,7 +526,7 @@ static inline bool read_string_ascii(
 	return true;
 }
 
-static inline bool read_string(
+NTLM_INLINE(bool) read_string(
 	char **out,
 	ntlm_client *ntlm,
 	ntlm_buf *message,
@@ -539,7 +539,7 @@ static inline bool read_string(
 		return read_string_ascii(out, ntlm, message, string_len);
 }
 
-static inline bool read_target_info(
+NTLM_INLINE(bool) read_target_info(
 	char **server_out,
 	char **domain_out,
 	char **server_dns_out,
@@ -965,7 +965,7 @@ static void des_key_from_password(
 	generate_odd_parity(out);
 }
 
-static inline bool generate_lm_hash(
+NTLM_INLINE(bool) generate_lm_hash(
 	ntlm_des_block out[2],
 	ntlm_client *ntlm,
 	const char *password)
diff --git a/src/unicode_builtin.c b/src/unicode_builtin.c
index 6d398b7..cb98f70 100644
--- a/src/unicode_builtin.c
+++ b/src/unicode_builtin.c
@@ -12,6 +12,7 @@
 #include "ntlm.h"
 #include "unicode.h"
 #include "compat.h"
+#include "util.h"
 
 typedef unsigned int    UTF32;   /* at least 32 bits */
 typedef unsigned short  UTF16;   /* at least 16 bits */
@@ -180,7 +181,7 @@ static ConversionResult ConvertUTF16toUTF8 (
  * definition of UTF-8 goes up to 4-byte sequences.
  */
 
-static inline bool isLegalUTF8(const UTF8 *source, int length) {
+NTLM_INLINE(bool) isLegalUTF8(const UTF8 *source, int length) {
     UTF8 a;
     const UTF8 *srcptr = source+length;
     switch (length) {
@@ -288,7 +289,7 @@ typedef enum {
 	unicode_builtin_utf16_to_8
 } unicode_builtin_encoding_direction;
 
-static inline bool unicode_builtin_encoding_convert(
+NTLM_INLINE(bool) unicode_builtin_encoding_convert(
 	char **converted,
 	size_t *converted_len,
 	ntlm_client *ntlm,
diff --git a/src/unicode_iconv.c b/src/unicode_iconv.c
index e14da21..ac53638 100644
--- a/src/unicode_iconv.c
+++ b/src/unicode_iconv.c
@@ -14,6 +14,7 @@
 #include "ntlmclient.h"
 #include "unicode.h"
 #include "ntlm.h"
+#include "util.h"
 #include "compat.h"
 
 typedef enum {
@@ -40,7 +41,7 @@ bool ntlm_unicode_init(ntlm_client *ntlm)
 	return true;
 }
 
-static inline bool unicode_iconv_encoding_convert(
+NTLM_INLINE(bool) unicode_iconv_encoding_convert(
 	char **converted,
 	size_t *converted_len,
 	ntlm_client *ntlm,
diff --git a/src/utf8.h b/src/utf8.h
index a26ae85..dd0bce8 100644
--- a/src/utf8.h
+++ b/src/utf8.h
@@ -1,30 +1,32 @@
-// The latest version of this library is available on GitHub;
-// https://github.com/sheredom/utf8.h
-
-// This is free and unencumbered software released into the public domain.
-//
-// Anyone is free to copy, modify, publish, use, compile, sell, or
-// distribute this software, either in source code form or as a compiled
-// binary, for any purpose, commercial or non-commercial, and by any
-// means.
-//
-// In jurisdictions that recognize copyright laws, the author or authors
-// of this software dedicate any and all copyright interest in the
-// software to the public domain. We make this dedication for the benefit
-// of the public at large and to the detriment of our heirs and
-// successors. We intend this dedication to be an overt act of
-// relinquishment in perpetuity of all present and future rights to this
-// software under copyright law.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
-// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
-// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
-// IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
-// OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
-// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
-// OTHER DEALINGS IN THE SOFTWARE.
-//
-// For more information, please refer to <http://unlicense.org/>
+/*
+ * The latest version of this library is available on GitHub;
+ * https://github.com/sheredom/utf8.h
+ *
+ * This is free and unencumbered software released into the public domain.
+ *
+ * Anyone is free to copy, modify, publish, use, compile, sell, or
+ * distribute this software, either in source code form or as a compiled
+ * binary, for any purpose, commercial or non-commercial, and by any
+ * means.
+ *
+ * In jurisdictions that recognize copyright laws, the author or authors
+ * of this software dedicate any and all copyright interest in the
+ * software to the public domain. We make this dedication for the benefit
+ * of the public at large and to the detriment of our heirs and
+ * successors. We intend this dedication to be an overt act of
+ * relinquishment in perpetuity of all present and future rights to this
+ * software under copyright law.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * For more information, please refer to <http://unlicense.org/>
+ */
 
 #ifndef SHEREDOM_UTF8_H_INCLUDED
 #define SHEREDOM_UTF8_H_INCLUDED
diff --git a/src/util.h b/src/util.h
index 70cf294..48e0169 100644
--- a/src/util.h
+++ b/src/util.h
@@ -12,6 +12,14 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#if defined(_MSC_VER)
+# define NTLM_INLINE(type) static __inline type
+#elif defined(__GNUC__)
+# define NTLM_INLINE(type) static __inline__ type
+#else
+# define NTLM_INLINE(type) static type
+#endif
+
 extern void ntlm_memzero(void *data, size_t size);
 extern uint64_t ntlm_htonll(uint64_t value);