diff --git a/include/ctype.h b/include/ctype.h
index 8f0d168..a6f44df 100644
--- a/include/ctype.h
+++ b/include/ctype.h
@@ -22,13 +22,18 @@ int   isxdigit(int);
 int   tolower(int);
 int   toupper(int);
 
+static __inline int __isspace(int _c)
+{
+	return _c == ' ' || (unsigned)_c-'\t' < 5;
+}
+
 #define isalpha(a) ((((unsigned)(a)|32)-'a') < 26)
 #define isdigit(a) (((unsigned)(a)-'0') < 10)
 #define islower(a) (((unsigned)(a)-'a') < 26)
 #define isupper(a) (((unsigned)(a)-'A') < 26)
 #define isprint(a) (((unsigned)(a)-0x20) < 0x5f)
 #define isgraph(a) (((unsigned)(a)-0x21) < 0x5e)
-
+#define isspace(a) __isspace(a)
 
 
 #if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
diff --git a/include/sched.h b/include/sched.h
index 4394b64..3e34a72 100644
--- a/include/sched.h
+++ b/include/sched.h
@@ -123,7 +123,7 @@ __CPU_op_func_S(XOR, ^)
 #define CPU_XOR(d,s1,s2) CPU_XOR_S(sizeof(cpu_set_t),d,s1,s2)
 #define CPU_COUNT(set) CPU_COUNT_S(sizeof(cpu_set_t),set)
 #define CPU_ZERO(set) CPU_ZERO_S(sizeof(cpu_set_t),set)
-#define CPU_EQUAL(set) CPU_EQUAL_S(sizeof(cpu_set_t),set)
+#define CPU_EQUAL(s1,s2) CPU_EQUAL_S(sizeof(cpu_set_t),s1,s2)
 
 #endif
 
diff --git a/include/stdlib.h b/include/stdlib.h
index f034c6e..db569d9 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -144,12 +144,12 @@ int mkostemps (char *, int, int);
 void *valloc (size_t);
 void *memalign(size_t, size_t);
 int getloadavg(double *, int);
+int clearenv(void);
 #define WCOREDUMP(s) ((s) & 0x80)
 #define WIFCONTINUED(s) ((s) == 0xffff)
 #endif
 
 #ifdef _GNU_SOURCE
-int clearenv(void);
 int ptsname_r(int, char *, size_t);
 char *ecvt(double, int, int *, int *);
 char *fcvt(double, int, int *, int *);
diff --git a/src/ctype/isspace.c b/src/ctype/isspace.c
index 7dff20d..231e907 100644
--- a/src/ctype/isspace.c
+++ b/src/ctype/isspace.c
@@ -1,5 +1,6 @@
 #include <ctype.h>
 #include "libc.h"
+#undef isspace
 
 int isspace(int c)
 {
diff --git a/src/env/__init_tls.c b/src/env/__init_tls.c
index 6cca968..ddc2a73 100644
--- a/src/env/__init_tls.c
+++ b/src/env/__init_tls.c
@@ -91,12 +91,11 @@ void __init_tls(size_t *aux)
 	libc.tls_size = 2*sizeof(void *)+T.size+T.align+sizeof(struct pthread);
 
 	if (libc.tls_size > sizeof builtin_tls) {
+#ifndef SYS_mmap2
+#define SYS_mmap2 SYS_mmap
+#endif
 		mem = (void *)__syscall(
-#ifdef SYS_mmap2
 			SYS_mmap2,
-#else
-			SYS_mmap,
-#endif
 			0, libc.tls_size, PROT_READ|PROT_WRITE,
 			MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
 		/* -4095...-1 cast to void * will crash on dereference anyway,
diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c
index 12f14f7..c90fe99 100644
--- a/src/ldso/dynlink.c
+++ b/src/ldso/dynlink.c
@@ -1603,10 +1603,14 @@ static int invalid_dso_handle(void *h)
 }
 void *dlopen(const char *file, int mode)
 {
+	strcpy(errbuf, "Dynamic loading not supported");
+	errflag = 1;
 	return 0;
 }
 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
 {
+	errflag = 1;
+	snprintf(errbuf, sizeof errbuf, "Symbol not found: %s", s);
 	return 0;
 }
 int __dladdr (const void *addr, Dl_info *info)
diff --git a/src/locale/pleval.c b/src/locale/pleval.c
index 961dabc..d60058d 100644
--- a/src/locale/pleval.c
+++ b/src/locale/pleval.c
@@ -28,14 +28,6 @@ struct st {
 	int op;
 };
 
-/* TODO: this should go into ctypes.h */
-#undef isspace
-#define isspace(a) __isspace(a)
-static __inline int __isspace(int _c)
-{
-	return _c == ' ' || (unsigned)_c-'\t' < 5;
-}
-
 static const char *skipspace(const char *s)
 {
 	while (isspace(*s)) s++;
diff --git a/src/misc/mntent.c b/src/misc/mntent.c
index 3eafba5..a16d652 100644
--- a/src/misc/mntent.c
+++ b/src/misc/mntent.c
@@ -10,7 +10,7 @@ FILE *setmntent(const char *name, const char *mode)
 
 int endmntent(FILE *f)
 {
-	fclose(f);
+	if (f) fclose(f);
 	return 1;
 }