diff --git a/Makefile b/Makefile
index 505d1a70..857bf421 100644
--- a/Makefile
+++ b/Makefile
@@ -47,6 +47,7 @@ SPORK_TAG?=master
 HAS_SHARED?=1
 DEBUGGER=gdb
 SONAME_SETTER=-Wl,-soname,
+STRIPFLAGS=-x -S
 
 # For cross compilation
 HOSTCC?=$(CC)
@@ -80,6 +81,12 @@ ifeq ($(UNAME), Darwin)
 	LDCONFIG:=true
 else ifeq ($(UNAME), Linux)
 	CLIBS:=$(CLIBS) -lrt -ldl
+else ifeq ($(UNAME), SunOS)
+	BUILD_CFLAGS+=-D__EXTENSIONS__ -DJANET_NO_NANBOX
+	BOOT_CFLAGS+=-D__EXTENSIONS__ -DJANET_NO_NANBOX
+	CLIBS:=-lsocket -lm
+	STRIPFLAGS=-x
+	LDCONFIG:=false
 endif
 
 # For other unix likes, add flags here!
@@ -289,7 +296,7 @@ build/janet-%.tar.gz: $(JANET_TARGET) \
 	README.md build/c/janet.c build/c/shell.c
 	mkdir -p build/$(JANET_DIST_DIR)/bin
 	cp $(JANET_TARGET) build/$(JANET_DIST_DIR)/bin/
-	strip -x -S 'build/$(JANET_DIST_DIR)/bin/janet'
+	strip $(STRIPFLAGS) 'build/$(JANET_DIST_DIR)/bin/janet'
 	mkdir -p build/$(JANET_DIST_DIR)/include
 	cp build/janet.h build/$(JANET_DIST_DIR)/include/
 	mkdir -p build/$(JANET_DIST_DIR)/lib/
@@ -336,7 +343,7 @@ build/janet.pc: $(JANET_TARGET)
 install: $(JANET_TARGET) $(JANET_LIBRARY) $(JANET_STATIC_LIBRARY) build/janet.pc build/janet.h
 	mkdir -p '$(DESTDIR)$(BINDIR)'
 	cp $(JANET_TARGET) '$(DESTDIR)$(BINDIR)/janet'
-	strip -x -S '$(DESTDIR)$(BINDIR)/janet'
+	strip $(STRIPFLAGS) '$(DESTDIR)$(BINDIR)/janet'
 	mkdir -p '$(DESTDIR)$(INCLUDEDIR)/janet'
 	cp -r build/janet.h '$(DESTDIR)$(INCLUDEDIR)/janet'
 	ln -sf ./janet/janet.h '$(DESTDIR)$(INCLUDEDIR)/janet.h'
diff --git a/README.md b/README.md
index 72c25d40..8324e1dd 100644
--- a/README.md
+++ b/README.md
@@ -213,6 +213,10 @@ gmake install-jpm-git
 NetBSD build instructions are the same as the FreeBSD build instructions.
 Alternatively, install the package directly with `pkgin install janet`.
 
+### illumos
+
+Building on illumos is exactly the same as building on FreeBSD.
+
 ### Windows
 
 1. Install [Visual Studio](https://visualstudio.microsoft.com/thank-you-downloading-visual-studio/?sku=Community&rel=15#) or [Visual Studio Build Tools](https://visualstudio.microsoft.com/thank-you-downloading-visual-studio/?sku=BuildTools&rel=15#).
diff --git a/src/core/os.c b/src/core/os.c
index 12802a9a..aa052a18 100644
--- a/src/core/os.c
+++ b/src/core/os.c
@@ -173,6 +173,8 @@ JANET_CORE_FN(os_which,
     return janet_ckeywordv("dragonfly");
 #elif defined(JANET_BSD)
     return janet_ckeywordv("bsd");
+#elif defined(JANET_ILLUMOS)
+    return janet_ckeywordv("illumos");
 #else
     return janet_ckeywordv("posix");
 #endif
@@ -312,6 +314,13 @@ JANET_CORE_FN(os_cpu_count,
         return dflt;
     }
     return janet_wrap_integer(result);
+#elif defined(JANET_ILLUMOS)
+    (void) dflt;
+    long result = sysconf(_SC_NPROCESSORS_CONF);
+    if (result < 0) {
+        return dflt;
+    }
+    return janet_wrap_integer(result);
 #else
     return dflt;
 #endif
diff --git a/src/include/janet.h b/src/include/janet.h
index 74d0661f..844884f8 100644
--- a/src/include/janet.h
+++ b/src/include/janet.h
@@ -77,6 +77,11 @@ extern "C" {
 #define JANET_CYGWIN 1
 #endif
 
+/* Check for Illumos */
+#if defined(__illumos__)
+#define JANET_ILLUMOS 1
+#endif
+
 /* Check Unix */
 #if defined(_AIX) \
     || defined(__APPLE__) /* Darwin */ \
@@ -162,7 +167,7 @@ extern "C" {
 #endif
 
 /* Check sun */
-#ifdef __sun
+#if defined(__sun) && !defined(JANET_ILLUMOS)
 #define JANET_NO_UTC_MKTIME
 #endif