diff --git a/libc/malloc/amalloc.c b/libc/malloc/amalloc.c
index c8579d4f2..2cd8001e9 100644
--- a/libc/malloc/amalloc.c
+++ b/libc/malloc/amalloc.c
@@ -70,11 +70,11 @@ static  NPTR allocp;   /*search ptr*/
 static  NPTR alloct;   /*arena top*/
 static  NPTR allocx;   /*for benefit of realloc*/
 
+static int debug_level = DEBUG;
 #if DEBUG
 #define ASSERT(p)   if(!(p))malloc_assert_fail(#p,__LINE__);else {}
 #define debug(...)  do { if (debug_level > 1) __dprintf(__VA_ARGS__); } while (0)
 #define debug2(...) do { if (debug_level > 2) __dprintf(__VA_ARGS__); } while (0)
-static int debug_level = DEBUG;
 static void malloc_assert_fail(char *s, int);
 static void malloc_show_heap(void);
 static int malloc_check_heap(void);
@@ -335,6 +335,7 @@ malloc_show_heap(void)
     unsigned int size, alloc = 0, free = 0;
     static unsigned int maxalloc;
 
+    if (!debug_level) return;
     debug2("--- heap size ---\n");
     malloc_check_heap();
     for(p = (NPTR)&allocs[0]; clearbusy(next(p)) > p; p=clearbusy(next(p))) {
diff --git a/libc/malloc/dprintf.c b/libc/malloc/dprintf.c
index fbd7e9ba4..eda959cff 100644
--- a/libc/malloc/dprintf.c
+++ b/libc/malloc/dprintf.c
@@ -44,8 +44,12 @@ int __dprintf(const char *fmt, ...)
     char b[80];
     static int fd = -1;
 
-    if (fd < 0)
-        fd = open(_PATH_CONSOLE, O_WRONLY);
+    if (fd < 0) {
+        if (!isatty(STDERR_FILENO))
+            fd = STDERR_FILENO;
+        else
+            fd = open(_PATH_CONSOLE, O_WRONLY);
+    }
     va_start(va, fmt);
     for (n = 0; *fmt; fmt++) {
         if (*fmt == '%') {
diff --git a/libc/malloc/v7malloc.c b/libc/malloc/v7malloc.c
index cdf88775f..04842ffff 100644
--- a/libc/malloc/v7malloc.c
+++ b/libc/malloc/v7malloc.c
@@ -59,11 +59,11 @@ static  NPTR allocp;   /*search ptr*/
 static  NPTR alloct;   /*arena top*/
 static  NPTR allocx;   /*for benefit of realloc*/
 
+static int debug_level = DEBUG;
 #if DEBUG
 #define ASSERT(p)   if(!(p))malloc_assert_fail(#p,__LINE__);else {}
 #define debug(...)  do { if (debug_level > 1) __dprintf(__VA_ARGS__); } while (0)
 #define debug2(...) do { if (debug_level > 2) __dprintf(__VA_ARGS__); } while (0)
-static int debug_level = DEBUG;
 static void malloc_assert_fail(char *s, int);
 static void malloc_show_heap(void);
 static int malloc_check_heap(void);
@@ -308,6 +308,7 @@ malloc_show_heap(void)
     unsigned int size, alloc = 0, free = 0;
     static unsigned int maxalloc;
 
+    if (!debug_level) return;
     debug2("--- heap size ---\n");
     malloc_check_heap();
     for(p = (NPTR)&allocs[0]; clearbusy(next(p)) > p; p=clearbusy(next(p))) {