diff --git a/Makefile b/Makefile
index 4011250c5..53e993d1b 100644
--- a/Makefile
+++ b/Makefile
@@ -340,23 +340,23 @@ cmakebuild:
 
 c90build: clean
 	$(CC) -v
-	CFLAGS="-std=c90" $(MAKE) allmost  # will fail, due to missing support for `long long`
+	CFLAGS="-std=c90 -Werror" $(MAKE) allmost  # will fail, due to missing support for `long long`
 
 gnu90build: clean
 	$(CC) -v
-	CFLAGS="-std=gnu90" $(MAKE) allmost
+	CFLAGS="-std=gnu90 -Werror" $(MAKE) allmost
 
 c99build: clean
 	$(CC) -v
-	CFLAGS="-std=c99" $(MAKE) allmost
+	CFLAGS="-std=c99 -Werror" $(MAKE) allmost
 
 gnu99build: clean
 	$(CC) -v
-	CFLAGS="-std=gnu99" $(MAKE) allmost
+	CFLAGS="-std=gnu99 -Werror" $(MAKE) allmost
 
 c11build: clean
 	$(CC) -v
-	CFLAGS="-std=c11" $(MAKE) allmost
+	CFLAGS="-std=c11 -Werror" $(MAKE) allmost
 
 bmix64build: clean
 	$(CC) -v
diff --git a/programs/util.h b/programs/util.h
index e8288b8fe..d6184fac8 100644
--- a/programs/util.h
+++ b/programs/util.h
@@ -324,6 +324,7 @@ UTIL_STATIC U32 UTIL_isDirectory(const char* infilename)
 UTIL_STATIC U32 UTIL_isLink(const char* infilename)
 {
 /* macro guards, as defined in : https://linux.die.net/man/2/lstat */
+#ifndef __STRICT_ANSI__
 #if defined(_BSD_SOURCE) \
     || (defined(_XOPEN_SOURCE) && (_XOPEN_SOURCE >= 500)) \
     || (defined(_XOPEN_SOURCE) && defined(_XOPEN_SOURCE_EXTENDED)) \
@@ -333,6 +334,7 @@ UTIL_STATIC U32 UTIL_isLink(const char* infilename)
     stat_t statbuf;
     r = lstat(infilename, &statbuf);
     if (!r && S_ISLNK(statbuf.st_mode)) return 1;
+#endif
 #endif
     (void)infilename;
     return 0;
diff --git a/zlibWrapper/examples/minigzip.c b/zlibWrapper/examples/minigzip.c
index 521d04711..f67be0956 100644
--- a/zlibWrapper/examples/minigzip.c
+++ b/zlibWrapper/examples/minigzip.c
@@ -18,6 +18,8 @@
 
 /* @(#) $Id$ */
 
+#define _POSIX_SOURCE /* fileno */
+
 #include "zstd_zlibwrapper.h"
 #include <stdio.h>
 
@@ -470,12 +472,8 @@ void file_compress(file, mode)
         exit(1);
     }
 
-#if !defined(NO_snprintf) && !defined(NO_vsnprintf)
-    snprintf(outfile, sizeof(outfile), "%s%s", file, GZ_SUFFIX);
-#else
     strcpy(outfile, file);
     strcat(outfile, GZ_SUFFIX);
-#endif
 
     in = fopen(file, "rb");
     if (in == NULL) {
@@ -510,11 +508,7 @@ void file_uncompress(file)
         exit(1);
     }
 
-#if !defined(NO_snprintf) && !defined(NO_vsnprintf)
-    snprintf(buf, sizeof(buf), "%s", file);
-#else
     strcpy(buf, file);
-#endif
 
     if (len > SUFFIX_LEN && strcmp(file+len-SUFFIX_LEN, GZ_SUFFIX) == 0) {
         infile = file;
@@ -523,11 +517,7 @@ void file_uncompress(file)
     } else {
         outfile = file;
         infile = buf;
-#if !defined(NO_snprintf) && !defined(NO_vsnprintf)
-        snprintf(buf + len, sizeof(buf) - len, "%s", GZ_SUFFIX);
-#else
         strcat(infile, GZ_SUFFIX);
-#endif
     }
     in = gzopen(infile, "rb");
     if (in == NULL) {
@@ -565,11 +555,7 @@ int main(argc, argv)
     gzFile file;
     char *bname, outmode[20];
 
-#if !defined(NO_snprintf) && !defined(NO_vsnprintf)
-    snprintf(outmode, sizeof(outmode), "%s", "wb6 ");
-#else
     strcpy(outmode, "wb6 ");
-#endif
 
     prog = argv[0];
     bname = strrchr(argv[0], '/');