diff --git a/bin/ar.cc b/bin/ar.cc
index 898f7aa..d6d3950 100644
--- a/bin/ar.cc
+++ b/bin/ar.cc
@@ -46,6 +46,7 @@
 #include <libintl.h>
 #include <mk/defs.h>
 #include <mksh/misc.h>		/* retmem_mb() */
+#include <ctype.h>
 
 struct ranlib {
 	union {
diff --git a/bin/doname.cc b/bin/doname.cc
index 85be203..9073de1 100644
--- a/bin/doname.cc
+++ b/bin/doname.cc
@@ -43,13 +43,18 @@
 #include <poll.h>
 #include <libintl.h>
 #include <signal.h>
+#if defined(sun) || defined(__sun)
+// XXX really needed, even on Solaris?
 #include <stropts.h>
+#else
+#endif
 #include <sys/errno.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/utsname.h>	/* uname() */
 #include <sys/wait.h>
 #include <unistd.h>		/* close() */
+#include <comp/namelen.h>
 
 /*
  * Defined macros
diff --git a/bin/main.cc b/bin/main.cc
index ed0afc0..e5aef91 100644
--- a/bin/main.cc
+++ b/bin/main.cc
@@ -48,14 +48,23 @@
 #include <sys/errno.h>		/* ENOENT */
 #include <sys/stat.h>		/* fstat() */
 #include <fcntl.h>		/* open() */
+#include <ctype.h>
 
+#if defined(sun) || defined(__sun)
 #	include <sys/systeminfo.h>	/* sysinfo() */
+#else
+#include <sys/sysinfo.h>
+#endif
 
 #include <sys/types.h>		/* stat() */
 #include <sys/wait.h>		/* wait() */
 #include <unistd.h>		/* execv(), unlink(), access() */
 #include <vroot/report.h>	/* report_dependency(), get_report_file() */
 
+#include <libintl.h> // gettext()
+
+#include <comp/progname.h>
+
 // From read2.cc
 extern	Name		normalize_name(register wchar_t *name_string, register int length);
 
@@ -69,7 +78,7 @@ extern void job_adjust_fini();
 #define	LD_SUPPORT_ENV_VAR_32	"SGS_SUPPORT_32"
 #define	LD_SUPPORT_ENV_VAR_64	"SGS_SUPPORT_64"
 #define	LD_SUPPORT_MAKE_LIB	"libmakestate.so.1"
-#ifdef __i386
+#if defined(__i386) || defined(__x86_64__)
 #define	LD_SUPPORT_MAKE_ARCH	"i386"
 #elif __sparc
 #define	LD_SUPPORT_MAKE_ARCH	"sparc"
@@ -197,7 +206,11 @@ main(int argc, char *argv[])
 
 	struct stat		out_stat, err_stat;
 	hostid = gethostid();
+#if defined(sun) || defined(__sun)
 	bsd_signals();
+#else
+// XXX necessary on linux?
+#endif
 
 	(void) setlocale(LC_ALL, "");
 
@@ -475,7 +488,11 @@ main(int argc, char *argv[])
 /*
  *	Enable interrupt handler for alarms
  */
+#if defined(sun) || defined(__sun)
         (void) bsd_signal(SIGALRM, (SIG_PF)doalarm);
+#else
+        (void) bsd_signal(SIGALRM, doalarm);
+#endif
 
 /*
  *	Check if make should report
@@ -1596,7 +1613,13 @@ make_install_prefix(void)
 	char origin[PATH_MAX];
 	char *dir;
 
-	if ((ret = readlink("/proc/self/path/a.out", origin,
+	if ((ret = readlink(
+#if defined(sun) || defined(__sun)
+            "/proc/self/path/a.out",
+#else
+            "/proc/self/exe",
+#endif
+            origin,
 	    PATH_MAX - 1)) < 0)
 		fatal("failed to read origin from /proc\n");
 
diff --git a/bin/misc.cc b/bin/misc.cc
index 25bad0a..05fee12 100644
--- a/bin/misc.cc
+++ b/bin/misc.cc
@@ -46,6 +46,10 @@
 #include <stdarg.h>		/* va_list, va_start(), va_end() */
 #include <vroot/report.h>	/* SUNPRO_DEPENDENCIES */
 #include <libintl.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <comp/progname.h>
 
 extern void job_adjust_fini();
 
diff --git a/bin/parallel.cc b/bin/parallel.cc
index c7712df..a7ffd00 100644
--- a/bin/parallel.cc
+++ b/bin/parallel.cc
@@ -46,8 +46,11 @@
 #include <sys/wait.h>
 #include <unistd.h>
 #include <netdb.h>
+#include <semaphore.h>
+
 #include <libintl.h>
 
+#include <comp/namelen.h>
 
 
 /*
@@ -252,7 +255,12 @@ execute_parallel(Property line, Boolean waitflg, Boolean local)
 #include <sys/ipc.h>		/* ftok() */
 #include <sys/shm.h>		/* shmget(), shmat(), shmdt(), shmctl() */
 #include <semaphore.h>		/* sem_init(), sem_trywait(), sem_post(), sem_destroy() */
+#if defined(sun) || defined(__sun)
 #include <sys/loadavg.h>	/* getloadavg() */
+#else
+#include <stdlib.h> // getloadavg()
+#define LOADAVG_1MIN 0
+#endif
 
 /*
  *	adjust_pmake_max_jobs (int pmake_max_jobs)
diff --git a/bin/read.cc b/bin/read.cc
index 0d47f5b..3cb3d3e 100644
--- a/bin/read.cc
+++ b/bin/read.cc
@@ -43,6 +43,7 @@
 #include <unistd.h>		/* read(), unlink() */
 #include <libintl.h>
 
+#include <comp/progname.h>
 
 /*
  * typedefs & structs
diff --git a/bin/read2.cc b/bin/read2.cc
index 50324de..2abab50 100644
--- a/bin/read2.cc
+++ b/bin/read2.cc
@@ -39,6 +39,8 @@
 #include <stdarg.h>		/* va_list, va_start(), va_end() */
 #include <libintl.h>
 
+#include <comp/progname.h>
+
 /*
  * Defined macros
  */
diff --git a/bin/state.cc b/bin/state.cc
index 57a0150..955fb7d 100644
--- a/bin/state.cc
+++ b/bin/state.cc
@@ -39,6 +39,11 @@
 #include <errno.h>		/* errno    */
 #include <locale.h>		/* MB_CUR_MAX    */
 
+#if defined(sun) || defined(__sun)
+#else
+#include <libintl.h> // gettext()
+#endif
+
 /*
  * Defined macros
  */
diff --git a/include/bsd/bsd.h b/include/bsd/bsd.h
index 2893d62..fdba250 100644
--- a/include/bsd/bsd.h
+++ b/include/bsd/bsd.h
@@ -32,6 +32,7 @@
 
 #include <signal.h>
 
+#if defined(sun) || defined(__sun)
 
 #ifndef __cplusplus
 typedef void (*SIG_PF) (int);
@@ -45,3 +46,5 @@ extern void (*bsd_signal(int, void (*) (int))) (int);
 extern void bsd_signals(void);
 
 #endif
+
+#endif
diff --git a/include/mk/defs.h b/include/mk/defs.h
index 5f5beab..a929e03 100644
--- a/include/mk/defs.h
+++ b/include/mk/defs.h
@@ -294,7 +294,11 @@ extern	long int	hostid;
  * Declarations of system defined variables
  */
 /* On linux this variable is defined in 'signal.h' */
+#if defined(sun) || defined(__sun)
 extern	char		*sys_siglist[];
+#else
+#include <signal.h>
+#endif
 
 /*
  * Declarations of system supplied functions
@@ -353,7 +357,9 @@ extern	wchar_t		*getmem_wc(register int size);
 #ifdef __cplusplus
 extern "C" {
 #endif
+#if defined(sun) || defined(__sun)
 extern	char		*getwd(char *);
+#endif
 #ifdef __cplusplus
 }
 #endif
diff --git a/include/mksh/defs.h b/include/mksh/defs.h
index 9ad58c4..4c13783 100644
--- a/include/mksh/defs.h
+++ b/include/mksh/defs.h
@@ -36,6 +36,9 @@
 #include <errno.h>		/* errno */
 
 #include <wctype.h>
+#include <wchar.h>
+
+#include <comp/timestruc_t.h>
 
 /*
  * A type and some utilities for boolean values
@@ -861,7 +864,12 @@ extern Boolean		do_not_exec_rule;		/* `-n' */
 extern Boolean		dollarget_seen;
 extern Boolean		dollarless_flag;
 extern Name		dollarless_value;
+// On Linux, environ is declared with C linkage in unistd.h
+// if _GNU_SOURCE is defined. Declaring it with C linkage here
+// should also be fine under Solaris.
+extern "C" {
 extern char		**environ;
+}
 extern Envvar		envvar;
 extern int		exit_status;
 extern wchar_t		*file_being_read;
diff --git a/lib/mksh/dosys.cc b/lib/mksh/dosys.cc
index 5ff0ab7..7c30a28 100644
--- a/lib/mksh/dosys.cc
+++ b/lib/mksh/dosys.cc
@@ -93,7 +93,13 @@ redirect_io(char *stdout_file, char *stderr_file)
 {
 	int	i;
 
+#if defined(sun) || defined(__sun)
 	(void) closefrom(3);
+#else
+        // XXX not available on Linux
+        // if necessary, could provide a compatibility function that
+        // iterates over /proc/$(getpid())/fd ...
+#endif
 	if ((i = my_open(stdout_file,
 	         O_WRONLY | O_CREAT | O_TRUNC | O_DSYNC,
 	         S_IREAD | S_IWRITE)) < 0) {
diff --git a/lib/mksh/misc.cc b/lib/mksh/misc.cc
index 4765102..db2cf29 100644
--- a/lib/mksh/misc.cc
+++ b/lib/mksh/misc.cc
@@ -49,6 +49,7 @@
 #include <sys/wait.h>		/* wait() */
 
 #include <string.h>		/* strerror() */
+#include <unistd.h>
 #include <libintl.h>
 
 
@@ -271,16 +272,33 @@ void
 enable_interrupt(register void (*handler) (int))
 {
 	if (sigivalue != SIG_IGN) {
+#if defined(sun) || defined(__sun)
 		(void) bsd_signal(SIGINT, (SIG_PF) handler);
+#else
+		(void) bsd_signal(SIGINT, handler);
+#endif
 	}
 	if (sigqvalue != SIG_IGN) {
+#if defined(sun) || defined(__sun)
 		(void) bsd_signal(SIGQUIT, (SIG_PF) handler);
+#else
+		(void) bsd_signal(SIGQUIT, handler);
+#endif
 	}
 	if (sigtvalue != SIG_IGN) {
+#if defined(sun) || defined(__sun)
 		(void) bsd_signal(SIGTERM, (SIG_PF) handler);
+#else
+		(void) bsd_signal(SIGTERM, handler);
+#endif
 	}
 	if (sighvalue != SIG_IGN) {
+#if defined(sun) || defined(__sun)
 		(void) bsd_signal(SIGHUP, (SIG_PF) handler);
+#else
+		(void) bsd_signal(SIGHUP, handler);
+#endif
+
 	}
 }
 
diff --git a/lib/vroot/lock.cc b/lib/vroot/lock.cc
index d3389ce..d31cb5e 100644
--- a/lib/vroot/lock.cc
+++ b/lib/vroot/lock.cc
@@ -36,10 +36,12 @@
 #include <errno.h>			/* errno */
 #include <libintl.h>
 
+#if defined(sun) || defined(__sun)
 extern	char		*sys_errlist[];
 extern	int		sys_nerr;
+#endif
 
-static	void		file_lock_error(char *msg, char *file, char *str, int arg1, int arg2);
+static	void		file_lock_error(char *msg, char *file, char *str, const char *arg1, const char *arg2);
 
 #define BLOCK_INTERUPTS sigfillset(&newset) ; \
 	sigprocmask(SIG_SETMASK, &newset, &oldset)
@@ -109,7 +111,7 @@ file_lock(char *name, char *lockname, int *file_locked, int timeout)
 
 		if (errno != EEXIST) {
 			file_lock_error(msg, name, (char *)"symlink(%s, %s)",
-			    (int) name, (int) lockname);
+			    name, lockname);
 			fprintf(stderr, "%s", msg);
 			return errno;
 		}
@@ -157,7 +159,7 @@ file_lock(char *name, char *lockname, int *file_locked, int timeout)
  * Format a message telling why the lock could not be created.
  */
 static	void
-file_lock_error(char *msg, char *file, char *str, int arg1, int arg2)
+file_lock_error(char *msg, char *file, char *str, const char *arg1, const char *arg2)
 {
 	int		len;