diff --git a/stb_image.h b/stb_image.h
index a935b36..1a04f42 100644
--- a/stb_image.h
+++ b/stb_image.h
@@ -899,11 +899,13 @@ STBIDEF const char *stbi_failure_reason(void)
    return stbi__g_failure_reason;
 }
 
+#ifndef STBI_NO_FAILURE_STRINGS
 static int stbi__err(const char *str)
 {
    stbi__g_failure_reason = str;
    return 0;
 }
+#endif
 
 static void *stbi__malloc(size_t size)
 {
diff --git a/stb_image_write.h b/stb_image_write.h
index a9bf66c..3316feb 100644
--- a/stb_image_write.h
+++ b/stb_image_write.h
@@ -247,17 +247,17 @@ STBIWDEF void stbi_flip_vertically_on_write(int flip_boolean);
 #define STBIW_UCHAR(x) (unsigned char) ((x) & 0xff)
 
 #ifdef STB_IMAGE_WRITE_STATIC
-static int stbi__flip_vertically_on_write=0;
 static int stbi_write_png_compression_level = 8;
 static int stbi_write_tga_with_rle = 1;
 static int stbi_write_force_png_filter = -1;
 #else
 int stbi_write_png_compression_level = 8;
-int stbi__flip_vertically_on_write=0;
 int stbi_write_tga_with_rle = 1;
 int stbi_write_force_png_filter = -1;
 #endif
 
+static int stbi__flip_vertically_on_write = 0;
+
 STBIWDEF void stbi_flip_vertically_on_write(int flag)
 {
    stbi__flip_vertically_on_write = flag;
diff --git a/stb_leakcheck.h b/stb_leakcheck.h
index 8874ce5..1f2aa73 100644
--- a/stb_leakcheck.h
+++ b/stb_leakcheck.h
@@ -13,6 +13,10 @@
 #undef realloc
 #endif
 
+#ifndef STB_LEAKCHECK_OUTPUT_PIPE
+#define STB_LEAKCHECK_OUTPUT_PIPE stdout
+#endif
+
 #include <assert.h>
 #include <string.h>
 #include <stdlib.h>
@@ -97,16 +101,16 @@ static void stblkck_internal_print(const char *reason, stb_leakcheck_malloc_info
    // without "long long" don't support 64-bit targets either, so here's the
    // compromise:
    #if _MSC_VER < 1400 // before VS 2005
-      printf("%s: %s (%4d): %8d bytes at %p\n", reason, mi->file, mi->line, (int)mi->size, (void*)(mi+1));
+      fprintf(STB_LEAKCHECK_OUTPUT_PIPE, "%s: %s (%4d): %8d bytes at %p\n", reason, mi->file, mi->line, (int)mi->size, (void*)(mi+1));
    #else
-      printf("%s: %s (%4d): %16lld bytes at %p\n", reason, mi->file, mi->line, (long long)mi->size, (void*)(mi+1));
+      fprintf(STB_LEAKCHECK_OUTPUT_PIPE, "%s: %s (%4d): %16lld bytes at %p\n", reason, mi->file, mi->line, (long long)mi->size, (void*)(mi+1));
    #endif
 #else
    // Assume we have %zd on other targets.
    #ifdef __MINGW32__
-      __mingw_printf("%s: %s (%4d): %zd bytes at %p\n", reason, mi->file, mi->line, mi->size, (void*)(mi+1));
+      __mingw_fprintf(STB_LEAKCHECK_OUTPUT_PIPE, "%s: %s (%4d): %zd bytes at %p\n", reason, mi->file, mi->line, mi->size, (void*)(mi+1));
    #else
-      printf("%s: %s (%4d): %zd bytes at %p\n", reason, mi->file, mi->line, mi->size, (void*)(mi+1));
+      fprintf(STB_LEAKCHECK_OUTPUT_PIPE, "%s: %s (%4d): %zd bytes at %p\n", reason, mi->file, mi->line, mi->size, (void*)(mi+1));
    #endif
 #endif
 }